Dominic Thiem will seek the advice of a specialist in Barcelona after suffering an injury scare ahead of Wimbledon next week.

Number two seed Thiem retired due to a wrist injury when 5-2 up in the opening set against Adrian Mannarino in the Mallorca Championships on Tuesday.

An MRI conducted at a Mallorca hospital was inconclusive, so the US Open champion will now undergo further tests.

In an update on Wednesday, Thiem wrote on social media: "Yesterday during the match I had a problem with my wrist.

"I went immediately to do an MRI at the hospital in Palma de Mallorca. The results weren't that clear and I have decided to go to Barcelona to check with a specialist.

"I hope I can get the results and a clear diagnosis in the next days."

The ATP 250 event continued without him in Mallorca, as Roberto Bautista Agut moved into the quarter-finals with a 6-3 7-5 triumph over Italian Stefano Travaglia.

More Spanish success on home soil arrived as Pablo Carreno Busta won 6-4 6-4 against Jiri Vesely.

In the doubles, Novak Djokovic and Carlos Gomez-Herrera saw off top seeds Marcel Granollers and Horacio Zeballos to reach the last four in that competition.

Djokovic appears to be enjoying himself as he continues to prepare for Wimbledon, saying: "This was a huge win for us, beating one of the best doubles players in the world after losing the first set.

"We are having a lot of fun on the court. I thought we played well even though we lost the first set."

There was a major upset at the Viking International in Eastbourne, meanwhile, with number one seed Gael Monfils suffering a shock last-16 defeat to Australia's Max Purcell – ranked number 283 in the world.

Purcell, who is only in the tournament as a lucky loser, claimed a huge 6-4 5-7 6-4 win in a battle lasting over two hours.

Monfils fired down 16 aces and fought back after being within two points of defeat in the second set but was ultimately beaten and has not made an ATP quarter-final since February 2020.

"It feels unbelievable," said Purcell. "I thought I'd come out and have a go. 

"I've struggled to get into any singles events over the past nine months and primarily played doubles, so to get on a run here, on my favourite surface, is great."

Purcell will take on Andreas Seppi – a comfortable winner over Emil Ruusuvuori – in the last eight.

While Monfils crashed out, there was less drama for the second and third seeds. 

Alex de Minaur won 6-3 6-4 against home hope Liam Broady, while Lorenzo Sonego was a 6-4 6-2 victor in his contest with John Millman.

Feliciano Lopez reached the milestone of 500 ATP Tour wins with a comeback victory over Karen Khachanov at the Mallorca Championships.

Lopez, who turns 40 in September, prevailed 4-6 6-2 6-4 against the sixth seed.

He is the 10th active player to reach 500 wins, after Roger Federer, Rafael Nadal, Novak Djokovic, Andy Murray, Richard Gasquet, Fernando Verdasco, Marin Cilic, Stan Wawrinka and Tommy Robredo.

"More than the 500 wins, the important thing to me is the chance to keep playing in these kinds of tournaments and to keep being competitive," Lopez told ATPTour.com.

"I didn’t expect to be able to play at the level I am on the ATP Tour at 40 years of age, which I will be in September."

Spanish veteran Lopez would have expected to be taking on Dominic Thiem next, but the world number five retired due to a wrist injury when 5-2 to the good in the opening set against Adrian Mannarino.

"It's nice for me to be in the quarter-finals, but winning this way is not so cool. I really like Dominic, he's such a nice guy and I hope he will be feeling better soon," Mannarino said. "I hope it is not so serious, especially right before Wimbledon."

Elsewhere on the Balearic island, top seed Daniil Medvedev breezed past Corentin Moutet 6-4 6-2, while Casper Ruud defeated Tennys Sandgren in straight sets.

At the Viking International in Eastbourne, there were mixed fortunes for Lopez's countrymen Alejandro Davidovich Fokina and Albert Ramos-Vinolas.

Fokina, seeded sixth, saw off Mikael Ymer 7-5 6-1, but number seven seed Ramos-Vinolas fell 6-4 6-3 to Emil Ruusuvuori.

Alexander Bublik defeated fellow Kazakh Mikhail Kukushkin is straight sets, while Jo-Wilfred Tsonga went down in similar fashion against Egor Gerasimov.

Andy Murray is hopeful 2021 will prove not to be his last appearance at Wimbledon.

The two-time tournament winner has been handed a wildcard for the grass-court grand slam in London, which was cancelled last year due to the coronavirus pandemic.

Murray also missed the 2018 and 2019 tournaments due to injury, so this year will be his first Wimbledon outing since reaching the quarter-finals in 2017, when the ailing Briton suffered a five-set defeat to Sam Querrey.

Ahead of his first Wimbledon appearance in four years, the 34-year-old hopes to play in many more, though he will savour the experience and take nothing for granted given his recent injury woe.

"To me it's not so much about me worrying about it being my last one, it's just something that I think about," Murray told Sky News.

"I don't want it to be my last Wimbledon, certainly I want to keep playing, I don't want to stop just now, so yeah I want to keep going.

"I've had so many injuries and so many setbacks you just don't really know what's round the corner.

"I want to approach each tournament and each match that I play like it's my last one so that I can get the most out of it.

"So that's why I want to prepare here well. I'm going into the bubble on Wednesday evening so I'm going to get there early to practise at Wimbledon. 

"Hopefully I've got some high quality practices – I'm practising with Marin Cilic and I practise with Roger Federer later in the week.

"I'm just trying to play with high quality grass court players to prepare me as best as possible." 

Murray, who has undergone two hip surgeries since he last played at Wimbledon, earned an impressive win on the grass over Benoit Paire at Queen's last week.

He then lost in straight sets to eventual champion Matteo Berrettini in round two.

As long as he can prepare properly and remain competitive, three-time grand slam champion Murray, who has also previously won the US Open, wants to battle on.

He added: "It's more about the body if I'm restricted in how I can prepare. 

"If I can't prepare properly to compete then that's when it's not fair on yourself to keep putting yourself out there, because you're not properly prepared and can't do yourself justice.

"So if that was the case and I was having to compromise on my training just to get out there on a match court and my results weren't good – that is something I'd look at. 

"But providing I can train and prepare well and I'm enjoying it I'll do it for as long as I can."

Matteo Berrettini became the first Queen's Club Championships debutant to carry off the singles trophy since Boris Becker, as the Italian landed the biggest title of his career.

The world number nine beat British hope Cameron Norrie 6-4 6-7 (5-7) 6-3 in the London showpiece match on Sunday, setting himself up ideally ahead of a Wimbledon mission later this month.

Whereas Becker was 17 when he triumphed at Queen's Club in 1985, going on to be champion at Wimbledon just weeks later, Berrettini is 25 years old and established as a leading player.

His big serve – an aspect of his game he shares with vintage Becker – proved a huge asset against Norrie as Berrettini served 19 aces and won 91 per cent of points when landing his first delivery.

Norrie could not forge a break point but did commendably well to force a deciding set in a match that lasted three minutes short of two hours.

Berrettini said he had experienced an "unbelievable week", lifting his first title at ATP 500 level, and he was blown away by the Becker link.

"If I think about his name and my name, it's crazy," he said in an on-court interview.

"I was dreaming about playing this tournament. I was watching when I was a kid and now I had the chance to lift the trophy. It's a dream come true."

Berrettini could be a threat to anyone if his serve fires at Wimbledon, and he was proud of how he fended off Norrie.

"I didn't check the numbers during the match. I knew I was serving well," said Berrettini. "I knew it was important because in the rallies this guy is dangerous. I knew I had to play my best tennis."

Berrettini said his celebrations were likely to be muted, given he is in a pre-Wimbledon bubble, predicting his team would limit his post-match treats to "probably room service and sparkling water".

There would be cause for greater cheer if Berrettini goes on a run at the All England Club, with Wimbledon due to begin on June 28. His previous best performance at Wimbledon was a run to the fourth round two years ago.

Berrettini told Amazon Prime: "I know it's going to be a really tough tournament.

"Probably all the players have extra motivation to play well there so it's going to be tough, but I have a lot of confidence."

Matteo Berrettini continued his impressive charge at the Queen's Club Championships as he booked a place in the final against Cameron Norrie.

Top seed Berrettini, ranked nine in the world, has not dropped a set all week.

His impressive run has seen him defeat home hopes Andy Murray and Dan Evans, with one more Briton in the shape of Norrie left to see off in his bid for glory.

Berrettini ensured he will be in the final by claiming a 6-4 6-4 triumph over fourth seed Alex de Minaur in the semi-final on Saturday.

The Italian dropped just four of his 36 points on first-serve and sent down eight aces, with De Minaur only able to force one break point in the entire contest, which he did not take.

"[Making the final] was the goal of the week and now I have one more step," said Berrettini.

"It is a great achievement, especially for the history of this tournament. I am really happy because to beat Alex, I had to play my best tennis."

Berrettini has four tour titles to his name, though this would be his first at ATP 500 level or above.

Victory would also represent the biggest win of Norrie's career – he has lost each of his three previous finals, all at ATP 250 level.

Norrie impressively eliminated Denis Shapovalov to reach the showpiece, beating the Canadian 7-5 6-3.

Shapovalov had earlier finished off a 6-3 6-4 quarter-final win over Frances Tiafoe, a match that could not be completed on Friday due to fading light.

But the second seed could not muster up another victory against a fresher Norrie.

At the Halle Open, Andrey Rublev reached his eighth final since the start of 2020, though his first on a grass court.

Rublev dropped his first set of the week but ultimately prevailed with a 6-1 3-6 6-3 semi-final victory over Nikoloz Basilashvili.

The Russian has won his last four finals at ATP 500 level and will seek a fifth on Sunday.

"It's my first final on grass and in Halle," he said. "I think I can play on every surface and I will try my best again.

"I had good opportunities to break Basilashvili in the second set, some quite easy forehands and I stressed a little showing my emotions. 

"I then came back and stayed calm, until the last game. But I won."

Rublev will take on unseeded Ugo Humbert, who held his nerve to edge a thriller against Felix Auger-Aliassime, winning 6-4 3-6 7-6 (7-5).

Humbert beat Alexander Zverev earlier in the week and has had to win a deciding set in all four rounds, while the beaten Auger-Aliassime had previously seen off Roger Federer as part of a dramatic event.

Frenchman Humbert won each of his first two career finals, which both took place last year in ATP 250 events.

Top seed Matteo Berrettini has his sights set on the Queen's Club Championships title after beating Dan Evans in the quarter-finals.

After a delay of more than four hours because of rain in London, Berrettini overcame Evans 7-6 (7-5) 6-3 to reach his third ATP grass-court semi-final.

The Italian hit 13 aces and won 81 per cent of his first-serve points against Evans to set up a last-four clash with Alex de Minaur. 

Berrettini improved his win-loss record to 24-6 for the season and laid out his ambition to walk away from the tournament with the trophy.

"I didn't serve that well, but I was returning well and I just played better in the last few points of the tie-break," he said.

"After that, I felt more confident. The conditions were really tough, windy and cold, so I took time to adapt a little bit. I am pretty happy with my performance.

"The court condition was really good. I expected slippery conditions, but it was like yesterday.

"I came here to win the tournament, that is my goal. Now I am two steps away. I am happy with the way I am playing, and my mental attitude is really good."

Up next for Berrettini is Australian De Minaur, who came from behind to defeat Marin Cilic 3-6 6-3 6-4.

The 22-year-old won 73 per cent (22/30) of his second-serve points and saved six of the seven break points he faced as he moved to 16-12 for the season.

In the battle of the British players, Cameron Norrie beat Jack Draper 6-3 6-3, while Denis Shapovalov was leading Frances Tiafoe 6-3 when their match was suspended due to fading light. They will resume on Saturday.

At the Halle Open, Andrey Rublev reached his sixth ATP Tour semi-final of the year thanks to a 7-6 (7-4) 6-2 win over 2011 champion Philipp Kohlschreiber.

"I am happy with my performance to reach the semi-finals for the first time," Rublev said. "The first set was really tough. He was 3-0 up in the tie-break and I came back, which was the key.

"After the first set, I think he mentally went down and I was pumped up. I hit a couple of good returns in the first game of the second set."

Russian Rublev will face Nikoloz Basilashvili in the last four after the Georgian defeated Lloyd Harris 6-4 7-6 (7-5). 

In the day's other quarter-finals, Felix Auger-Aliassime beat Marcos Giron 6-3 6-2 and Ugo Humbert overcame Sebastian Korda 6-2 6-7 (5-7) 6-4.

Dominic Thiem has joined Rafael Nadal in announcing he will not compete at the Olympic Games in Tokyo.

The 27-year-old US Open champion pinned his decision on the belief he would struggle to find his best form, having endured a tough 2021 season so far.

Thiem has lost his last three matches, including a first-round defeat to Pablo Andujar at the French Open, and has an overall 9-8 win-loss record for the year.

World number five Thiem confirmed, however, that he intends to play Wimbledon, which begins on June 28, and will then focus on getting in the best possible shape for his grand slam title defence at Flushing Meadows.

Nadal said earlier on Thursday that he would play neither Wimbledon nor the Olympics, where the tennis tournament starts on July 24, because he wished to recover from his clay-court season efforts.

Women's tour superstar Naomi Osaka has elected to miss Wimbledon but said on Thursday she would represent Japan at her home Olympics.

Thiem revealed his Olympics decision in a statement posted on his Twitter page, saying: "After talking with my team and analysing the situation I have taken the very difficult decision to withdraw from competing in the Tokyo Olympics.

"For me, like all athletes, taking part in the Olympics and representing my country is a huge honour and that makes this decision even tougher. However, 2021 did not start as expected and I don't feel ready to play my best in Tokyo.

"These last two weeks I have been training hard – and I’m starting to improve my conditioning and concentration little by little. My goal is to work hard the coming weeks, give my best at Wimbledon and keep training and hopefully defend my US Open title.

"I wish the entire Austrian team traveling to Tokyo all the best. I am young and I hope to be able to play for Austria at the Olympics in Paris 2024."

Top seed Matteo Berrettini beat Andy Murray to reach the quarter-finals at Queen's Club and Ugo Humbert upset Alexander Zverev at the Halle Open on Thursday.

Murray, a five-time champion at Queen's, was beaten 6-3 6-3 by Italian Berrettini as the three-time grand slam champion struggled a day on from being given a Wimbledon wildcard.

The former world number one beat Benoit Paire in his first ATP Tour singles match since March on Tuesday, but the 34-year-old revealed he is still being troubled by a groin injury after his loss to Berrettini and knows he must raise his game.

Murray said: "I actually felt my movement was actually quite good for both of the matches. My tennis today was not very good. That's the thing that I'll need to improve the most.

"Then there is still a slight niggle in the groin, so [I have] to try to get rid of that discomfort between now and Wimbledon. I need to be playing points, basically. I played two sets in preparation for this event.

"I do feel like I genuinely have been hitting the ball well in practice, but then like today when you're under a bit more pressure and stuff and you're having to make very split-second decisions when you're on the court, if the guy is serving 140 miles an hour, like, it's difficult to prepare for that."

Dan Evans made history earlier in the day, getting the better of Adrian Mannarino 6-4 7-6 (9-7).

With Jack Draper and Cameron Norrie having already progressed, Evans' win ensured there will be three Britons in the singles quarter-finals for the first time in the Open Era.

Feliciano Lopez will not retain his title in London after the Spaniard went down 6-2 6-3 to second seed Denis Shapovalov. Spanish veteran Lopez won in 2019, with last year's tournament cancelled due to the pandemic.

There will be no glory on home soil in Halle for German Zverev, who was taken out 7-6 (7-4) 3-6 6-3 by unseeded Frenchman Humbert.

Humbert has now beaten a top-10 player on every surface, with Zverev serving 20 aces but bowing out after his 22-year-old opponent claimed the only break of the final set.

Sebastian Korda battled past Kei Nishikori 2-6 6-3 7-5 in Halle, while Lloyd Harris also moved into the last eight at Lukas Lacko's expense.

The US Open is set to be the first tennis grand slam to operate at full spectator capacity for its duration since COVID-19 became a global crisis.

Tournament organisers said on Thursday that the major, which was played behind closed doors in 2020, would not impose reduce attendance measures this year.

"New York is back, and so are the fans," a statement on the tournament's website said. "The 2021 US Open will welcome fans back to the USTA Billie Jean King National Tennis Center at 100 per cent capacity for the two-week tournament."

Mike Dowse, chief executive of the United States Tennis Association (USTA), said: "We are extremely excited to be able to welcome our incredible fans back to the US Open this year.

"While we were proud that we were able to hold the event in 2020, we missed having our fans on-site, because we know that they are a large part of what makes the US Open experience unlike any other.

"Indeed, the challenges presented by the pandemic were tough on us all, but our sport came together like never before and tackled each challenge head on."

Dowse added: "Our sport surged in the toughest of times, and this year's US Open promises to be an unforgettable celebration of the game, those who play it, and those who revel in it."

The tournament added that it would follow all COVID-related guidelines, although its intention clearly is to run the major in as normal a manner as is possible.

The US Open's announcement came on the day tickets went on sale for the upcoming Wimbledon championship, which begins on June 28. The grass-court slam was cancelled last year.

Wimbledon will operate at a 50 per cent attendance restriction for much of its duration, although the weekend of the finals is due to see Centre Court at 100 per cent capacity.

The French Open functioned with a vastly reduced number of tickets available in both its 2020 and 2021 editions, compared to previous years.

The Australian Open in February capped spectator numbers at 30,000, although a snap lockdown in Melbourne meant there were no crowds for five days midway through the event, with Rod Laver Arena then limited to approximately 50 per cent capacity for the closing stretch of the event.

Naomi Osaka and Dominic Thiem won the women's and men's singles titles at the 2020 US Open, and this year's tournament runs from August 30 to September 12.

Roger Federer lost in the opening two rounds at the Halle Open for the first time in his career as his hopes of winning the title for the 11th time were ended by Felix Auger-Aliassime.

Federer beat Ilya Ivashka in his opening match of the grass-court season at a tournament defined by his dominance in Halle.

He came into Wednesday's clash with Auger-Aliassime boasting a 32-0 record in the first two rounds, and that looked set to be preserved after the 20-time grand slam champion won the first set.

But Auger-Aliassime, exactly 19 years Federer's junior, staged a stunning fightback in a contest with the largest age difference of the Swiss' 1,521 career matches.

His remarkable turnaround saw the Canadian claim a 4-6 6-3 6-2 triumph that marked the fourth top-10 win of his career.

It also meant he denied Federer a 70th match win in Halle and his 18th quarter-final in as many appearances at the tournament.

"It's a great victory, it's good for my confidence. It was already a great challenge for me to play a player like Roger, but to beat him, it's a great thing," Auger-Aliassime said. "It makes me really happy. But at the end, it's the quarter-finals in two days. 

"If it was the final, then I'd be really happy… it's another step in the tournament, it's a great match, so hopefully I can keep on going like that.

"In the first set, I didn’t think I could have played much better outside of just missing one forehand in my service game and then he hit two amazing passing shots and I was just like 'Whoa'.

"I understand how good he is and how good he was when he was No. 1 in the world, so it was tough.

"Everything worked well today, to be honest. I think that's what you need to do against Roger. On my part, I served really well. I was able to put in a lot of returns, mix up coming to the net, closing well. I think overall I did a good match."

Marcos Giron is next for Auger-Aliassime after he overcame Jan-Lennard Struff in three sets. There were straight-sets wins for Andrey Rublev over Jordan Thompson and Philipp Kohlschreiber over Corentin Moutet. Rublev will face Kohlschreiber in the last eight.

Wednesday's play at the Queen's Club Championships saw Alex de Minaur win an all-Australian clash with John Millman, while Britons Cameron Norrie and Jack Draper defeated Aslan Karatsev and Alexander Bublik respectively.

Former world number ones Andy Murray and Venus Williams have been given Wimbledon wildcards.

Three-time grand slam champion Murray missed the French Open to focus on the grass-court season, having been troubled by a groin injury.

The 34-year-old Brit, ranked 124th in the world, was emotional after beating Benoit Paire 6-2 6-2 in his first ATP Tour singles match since March on Tuesday.

Murray's career was in doubt after he underwent hip resurfacing in 2019, but the 34-year-old double Wimbledon champion will play in his home major at the All England Club.

Williams, a winner of five Wimbledon singles titles and a six-time doubles champion at the grass-court major, also received a wild card after dropping out of the top 100 in the rankings.

The 40-year-old American will be in the singles draw 21 years after winning her first Wimbledon title.

Wimbledon did not take place last year due to the coronavirus pandemic, but will be the first major outdoor sports in England to be staged with full capacity crowds for the finals weekend of July 10-11.

The Championships will start at SW19 on June 28 with 50 per cent capacity across the venue grounds, Centre Court and No.1 Court. Smaller show courts will be allowed to open at 75 per cent capacity from day one.

From the fourth round, the aim is to increase allocations for Centre Court and No.1 Court, rising to 100 per cent for the finals.

Andy Murray had to hold back the emotion as he celebrated a winning return to the ATP Tour at Queen's.

Murray had hip surgery in 2019 and had not won a grass-court game since 2018, with last year's season having been cancelled due to the coronavirus pandemic.

Having struggled with a groin injury, the 34-year-old Scot last played in March, yet showed flashes of his old self in his 6-3 6-2 victory over Benoit Paire, having taking up a wildcard into the pre-Wimbledon tournament.

It was an emotional moment for Murray, who said: "Look, I love playing tennis."

The five-time champion was fighting back the tears as he continued: "Obviously, competing is why you put in all the hard work.

"The last few years, I've not got to do that as much as I would have liked so, yeah it's just great that I'm out here and able to compete again.

"The body is old, but I did quite well today in terms of my movement.

"It's my first match on grass in three years and I've only played three or four practice sets in the build-up to this, so I didn't know exactly how I was going to play or feel – but I think for a first match it was good."

Murray will face top seed and world number nine Matteo Berrettini, who defeated Stefano Travaglia 7-6 (7-5) 7-6 (7-4).

British number one Dan Evans beat Alexei Popyrin, while fourth seed Alex de Minaur also progressed to round two, having come from behind against Laslo Djere. Second seed Denis Shapovalov overcame Aleksandar Vukic.

Tuesday's results mean, for the first time since 2005, four British players have won at Queen's, with Cameron Norrie and Jack Draper having gone through on Monday.

Meanwhile, after losing to Stefanos Tsitsipas in the French Open quarter-finals, world number two Daniil Medvedev crashed out of the Halle Open in the first round.

Jan-Lennard Struff was his conqueror, claiming a 7-6 (8-6) 6-3 triumph, which the German labelled as "the biggest win of my career."

There was better luck for third seed Alexander Zverev, though he did need three sets to see off Dominik Koepfer 6-4 3-6 6-3, just four days after facing Tsitsipas in the Roland Garros semi-finals.

Ugo Humbert awaits Zverev, while Felix Auger-Aliassime beat Hubert Hurkacz to tee up a tie with Roger Federer. World number seven Andrey Rublev got the better of Karen Khachanov.

There will be capacity crowds for the Wimbledon finals next month and around 45,000 people are set to be allowed into Wembley for the Euro 2020 semi-finals and final.

Prime Minister Boris Johnson on Monday announced a four-week delay in lifting coronavirus lockdown restrictions in England to July 19 due to rising cases of the Delta variant.

However, Wimbledon and the European Championship are being treated as test events, so there is set to be a full house of 15,000 on Centre Court for the championship matches on the weekend of July 10-11.

The grass-court grand slam will be the first outdoor sporting event to have a capacity crowd since the start of the pandemic.

When the tournament, which was not staged last year due to the COVID-19 crisis, starts on June 28 it will be at 50 per cent capacity.

A statement from the All England Club said: "We are pleased to have worked closely with the government, public health bodies, and our local authority in Merton, to confirm that, as part of this next phase of pilot events, The Championships 2021 will begin on Monday 28 June with 50 per cent capacity across the Grounds, building to full capacity crowds of 15,000 on Centre Court for the finals weekend.

"This will enable us to fulfil our aspiration of staging the best Wimbledon possible within the current circumstances, with the health and safety of all those who make Wimbledon happen - our guests, competitors, members, staff, media, officials, local residents, and partners - remaining our highest priority."

Crowds for England's first two Euro 2020 group games at Wembley have been capped at 22,500, but that figure is expected to be doubled so the stadium is half full for the semi-finals and final.

The semi-finals will be staged on July 6 and 7, with the final held on July 11.

Culture Secretary Oliver Dowden said: "We want to gather further evidence on how we can open up all big events safely, and for good.

"The expansion of trials of the NHS app and lateral flow testing will mean that bigger crowds will be able to attend a limited number of major sporting and cultural events early this summer as part of our events research programme.

"In the next few weeks, this means more fans enjoying the Euros and Wimbledon, and some of our biggest cultural and sports events."

Roger Federer returned to action at the Halle Open on Monday and won his first match on grass since the 2019 Wimbledon final.

Federer has endured two torrid years on the ATP Tour, missing most of 2020 due to double knee surgery.

The 20-time grand slam champion had then been limited to six matches this season heading into this week.

Having finally found some momentum at the French Open, Federer withdrew from his fourth-round match and explained: "It's important that I listen to my body and make sure I don't push myself too quickly on my road to recovery."

But the Swiss great was fit to finally step back out on a grass court for the first time since coming up short against Novak Djokovic at the All England Club.

And it was a winning return as Federer battled past Ilya Ivashka 7-6 (7-4) 7-5 in Germany.

Ivashka squandered two break point opportunities early in the opener and was quickly on the back foot after the set went to a tie-break, saving three set points but not a fourth.

Federer stayed patient in a second that stayed on serve initially, belatedly piling on the pressure to break in the final game having earlier passed up a match point at 5-4.

Fifth seed Federer was the only seed to win on Monday, however, as Sebastian Korda upset Roberto Bautista Agut in straight sets and David Goffin gave Corentin Moutet a walkover.

There was a standout shock at the Queen's Club Championships, too, as talented teenager Jannik Sinner was pipped by home hopeful Jack Draper 7-6 (8-6) 7-6 (7-2).

Draper's compatriot Cameron Norrie joined him in the last 16, battling back to beat Albert Ramos-Vinolas in three.

Novak Djokovic is chasing more records following his history-making triumph after the world number one's French Open crown brought him closer to rivals Rafael Nadal and Roger Federer in the race for tennis supremacy.

Djokovic became the first man in the Open Era to claim two or more titles at each of the four grand slams thanks to Sunday's stunning 6-7 (6-8) 2-6 6-3 6-2 6-4 victory over Stefanos Tsitsipas.

Serbian star Djokovic was two sets down on Court Philippe Chatrier, where he also became the first player in the Open Era to win a slam from two sets behind for his 19th major crown.

"I am thrilled and I'm very proud of this achievement," Djokovic – who upstaged clay specialist and defending champion Nadal in the semi-finals – told reporters afterwards. "I think part of the history of the sport that I love with all my heart is always something that is very inspiring and very fulfilling for me.

"I couldn't be happier and more satisfied with this kind of scenario in the last 48 hours. Probably ranks at the top three all-time achievements and experiences that I had in my professional tennis career. Going through a four-and-a-half battle with Rafa on his court, then bouncing back after not practicing yesterday, just coming in today with as much as recharged batteries and energy regained to fight another battle of four-and-a-half hours against Tsitsipas, who is playing in his first grand slam finals.

"It's always, of course, a bit tricky because you're playing for your trophy, for your first grand slam trophy, but you don't have much to lose. So I knew that he's going to probably start off very well, which was the case. It was a very close first set. Kind of gone a different way, but he was just the better player in those clutch moments. Second set I dropped physically and mentally I think a little bit. I just got fatigued a bit, just allowed him to kind of dominate the second set pretty much.

"Then went out from the court, as was the case against [Lorenzo] Musetti in the fourth round when I was two sets down, and came back as a different player. Just refreshed, managed to make a break, early break in the third. After that, I felt like I got into his head. I feel like I started swinging through the ball better. The momentum was on my side, it shifted. There was no looking back from that moment."

Djokovic is now just one trophy shy of equalling the record for most grand slam singles titles on the men's tour, currently shared by Nadal and Federer.

The 34-year-old insisted he will continue to chase records, with the ageing Nadal and Federer firmly in his sight.

"I never thought it was a mission impossible to reach the grand slams of these guys," Djokovic said. "I'm not there, but it's one less. But they are still playing. Obviously, they're playing great, especially Rafa with his level. We all have still opportunities at Wimbledon, all the other slams.

"You have four slams a year, so we're all competing for this amazing achievement and amazing trophies. I'll keep on going. I'll keep on chasing. At the same time, I'll keep on paving my own path, which is my own authentic path. We all three of us have our own journeys, and that's it."

Among those records is the golden grand slam – winning all four calendar majors as well as gold at the Olympic Games – with Wimbledon, the rescheduled Tokyo Games and US Open still to come in 2021 following his Australian Open success.

"Everything is possible. Definitely in my case I can say that what I've been through in my career, in my life, this journey has been terrific so far," added Djokovic. "I've achieved some things that a lot of people thought it would be not possible for me to achieve. Everything is possible, and I did put myself in a good position to go for the golden slam.

"But, I was in this position in 2016 as well. It ended up in a third-round loss in Wimbledon. This year we have only two weeks between the first round of Wimbledon and the finals here, which is not ideal because you go from really two completely different surfaces, trying to make that transition as smooth as possible, as quickly and efficiently as possible. So obviously I will enjoy this win and then think about Wimbledon in a few days' time.

"I don't have an issue to say that I'm going for the title in Wimbledon. Of course, I am. I was really happy to know that we are going to play Wimbledon this year, considering we haven't played it last year. I've had great success in the last couple of Wimbledon seasons that were played. I won in '18 and '19 there. Hopefully, I can keep that run going. I like the grass. Over the years I think I improved on grass, I adjusted my game. Hopefully, I can use this confidence that I have right now into Wimbledon, as well. Then let's take it from there."