Crowd favourite Bianca Andreescu was made to work as she opened her defence of the National Bank Open title she won two years ago but the Canadian eventually prevailed in Montreal. 

Andreescu defeated Harriet Dart 6-1 3-6 6-3 in just over two hours in her first match since falling to Alize Cornet in the opening around at Wimbledon. 

That was the latest in a disappointing string of results for Andreescu, who also departed Roland Garros after one match, but the world number eight got back on track Tuesday. 

"Playing at home is so, so awesome," Andreescu said in her on-court interview. "You guys [the fans] show me so much love, especially tonight. I've never had this kind of support before, so I'm so, so grateful."

While Andreescu was able to navigate a challenging opener, three other seeded players were not as fortunate. 

Katerina Siniakova downed fifth seed Garbine Muguruza 6-2 0-6 6-3, while Camila Giorgi ousted ninth seed Elise Mertens 6-3 7-5 and Liudmila Samsonova defeated 12th seed Elena Rybakina 6-4 5-7 6-4.

Having a better time of it were seventh-seeded Petra Kvitova, the 2012 tournament champion, and number 10 seed Anastasia Pavlyuchenkova, who won by identical 6-4 6-4 scorelines against Frenchwomen Fiona Ferro and Carolina Garcia, respectively. 

Eighth-seeded Victoria Azarenka waited out a rain delay to cruise past 2013 finalist Sorana Cirstea 6-2 6-2 in the final match of the day. 

In other action, 15th seed Coco Gauff handled Anastasija Sevastova 6-1 6-4 while her countrywoman Danielle Collins continued rolling after her title in San Jose last week, rallying past Jil Teichmann 4-6 6-1 6-3 for her 11th consecutive match win. 

Two more Americans, Sloane Stephens and Jessica Pegula, prevailed in three sets as well. 

Johanna Konta returned to the court after missing Wimbledon and the Tokyo Olympics due to coronavirus-related issues and advanced when Zhang Shuai was forced to retire up 6-4 2-5 with a leg injury. 

Karolina Muchova was a casualty in the first round of the National Bank Open as she was stunned by Oceane Dodin in Montreal on Monday.

The 14th seed was undone by the French qualifier despite Dodin sending down 10 double faults.

The 6-3 1-6 6-2 success was Dodin's first over a top-25 player this season.

Former U.S. Open finalists and 16th seed Madison Keys was also a first-round casualty, going down 6-3 6-3 to Canadian Rebecca Marino.

Toronto-born Marino, currently ranked 220th in the world, won in one hour and six minutes, converting four of her eight break points, while she saved four from five too.

However, there were no such problems for Ons Jabeur, the 13th seed strolling to a 6-1 6-3 victory over Clara Burel.

Eleventh seed Maria Sakkari also had a routine day, her opponent Marie Bouzkova unable to continue with Sakkari ahead 6-4 3-1.

An Olympic gold medallist in the doubles at Tokyo 2020, Katerina Siniakova had more to celebrate in the singles with a 6-1 6-3 win over long-time rival Jelena Ostapenko.

Elsewhere in the draw, Paula Badosa, Sorana Cirstea, Amanda Anisimova, Nadia Podoroska and Fiona Ferro all progressed.

With summer's main events about to begin, no one on the WTA tour is hotter than Danielle Collins. 

Two weeks after winning her maiden title in Palermo, Collins claimed the Silicon Valley Classic crown in San Jose, California by defeating Daria Kasatkina 6-3 6-7 (10-12) 6-1 on Sunday.

It was the 10th successive match victory for the American, who is ranked 36th in the world and poised to move up as the hard-court season intensifies with WTA 1000 events at Montreal and Cincinnati ahead of the U.S. Open. 

While it appeared for a while that Collins would cruise to another easy win, Kasatkina made it a fight in the 73-minute second set. 

The Russian had prevailed in the two previous meetings between the players, and she saved two championship points down 4-5 in the second and three more in winning the tiebreak. 

That marked only the second set Collins has dropped during her 10-match run, the other coming against Sloane Stephens in the second round earlier this week. 

Kasatkina's momentum was short-lived, however, as Collins broke her serve early in the third and never looked back.

Before her clay-court title run at Palermo, Collins had been 0-6 in semi-finals in her career. 

Andrea Petkovic claimed her first singles title on the WTA Tour in over six years thanks to an emphatic victory over Mayar Sherif at the Winners Open.

Petkovic was far too strong for her Egyptian opponent in Sunday's final, easing to a 6-1 6-1 triumph after just over an hour on court in Cluj-Napoca.

The impressive result sealed the German a seventh tournament win in her career, though she had not reigned at an event since her success in Antwerp back in February 2015.

Sherif had become the first Egyptian to reach a singles final on the WTA Tour and received praise from her opponent during the presentation ceremony.

"This has been a great week, but not only that, what's really important is you're paving the ground for all the girls in a part of the world which doesn't appreciate tennis as much as we do here in Europe," Petkovic said to the 25-year-old.

"It's so much more important than winning every title every week, though I'm sure you will get there as well. 

"Just being out there competing, being the first Egyptian woman to make a WTA final, to break into the top 100, I think that's incredible. I want to congratulate you on that – keep going."

Petkovic raced into a 5-0 lead in the opening set before Sherif held serve; she also survived two break points to move ahead at the start of the second.

However, the second seed reeled off the next six games in a row, clinching the result with a forehand winner.

Roger Federer turned 40 on Sunday amid uncertainty over whether he will grace the stage of a grand slam again.

Both he and Serena Williams, who reaches the same birthday landmark in September, have kept their future plans under wraps.

However, it would come as no surprise now if one, or both, were to retire by the end of the year.

Injuries are taking their toll, and even the greatest champions cannot go on forever.

Stats Perform looked at both Federer and Williams, considering what they may still want to achieve, and their prospects of attaining those remaining goals.

Federer's final fling?

Ahead of his 30th birthday, Federer was asked what it felt like to hit such a milestone.

"Birthdays happen. They're part of life," Federer said. "I'm happy I'm getting older. I'd rather be 30 than 20, to be honest. To me it's a nice time."

A decade on, Federer has good reason to be satisfied with life as he chalks up another decade. Family life is good, he'll never need to borrow a dollar, and he has advanced from 16 grand slams to 20.

But the knees would sooner be 30 than 40, and Federer, remarkable sportsman though he is, looks to have entered the lap of honour stage of his career – if he can even complete such a lap.

Two knee operations in 2020 were followed by a setback that ruled him out of the Olympics and will also keep him sidelined for the Toronto and Cincinnati tournaments before the US Open.

Will Federer make it to Flushing Meadows, where he won five successive titles at the height of his career? There has to be doubt over that, and should he indeed be an absentee in New York, what is there left to target? The Laver Cup, perhaps, a tournament in which he is financially invested and which is due to be played in Boston in late September.

Would he play on in 2022? Could he tolerate more long road trips without his family, living in a tennis bubble?

Target: Federer has never settled for second best, and it may have dawned on him at Wimbledon that in all probability he no longer can win a grand slam. Losing a 6-0 set to Hubert Hurkacz on the way to a quarter-final exit would have hurt. The hunger does not go away after 20 grand slams, but Federer's battle-weary body is sending him messages. He will want to go out on his own terms, which means getting fully fit.

Prospects: Assuming the knee issue is not a major problem, and more of a niggle, then Federer could still play the US Open, Laver Cup, Indian Wells and Paris Masters this year. If the mind is willing but the body does not comply, however, then it would not be a shock to see him call time before the Australian Open comes around in January.

Serena still one short of Court

From precocious teenager to queen of the tour, Williams' tennis journey has been a 25-year odyssey and there is nobody more driven to succeed than the great American.

It is an intense frustration that she remains rooted on 23 grand slams, one short of Margaret Court's record haul, and the four grand slam final losses she has suffered while on that mark have been cruel blows.

As her 40th birthday approaches on September 26, prospects of matching Court are fading. The leg injury that cruelly forced her out of Wimbledon in the first round was a harrowing turn of events, given she looked primed to be a big title challenger in London.

She is becoming less of a factor when looking at title favourites, but Williams is still capable of beating top players, still a threat wherever she shows up. It comes down to whether the body lets her chase her goals, and whether the pain of so many near-misses in recent years persuades this great champion the exertion is no longer worth prolonging.

Target: The 24th slam has been the must-have for Williams. Tour titles feel like an irrelevance, and Williams has won just one of those since January 2017, her calendar built around peaking for the majors since returning from giving birth to daughter Olympia.

Prospects: Beating Aryna Sabalenka and Simona Halep at the Australian Open demonstrated Williams still has the game for the big stage, and a semi-final defeat to Naomi Osaka, to whom she has now lost in three of four encounters, should not particularly detract from that. Wimbledon felt like a golden opportunity, with a host of major rivals absent and others struggling for form. There is no doubt she felt that way. Getting to 24 – and beyond – has shifted from feeling like an inevitability to being an odds-against chance now.

Top seed Elise Mertens was knocked out as Daria Kasatkina won through to the Silicon Valley Classic final where she will meet Danielle Collins.

Fourth seed Kasatkina swept aside world number 17 Mertens in one hour and 21 minutes, winning 6-3 6-2 in San Jose.

The 24-year-old Russian progresses to her fourth final of the WTA season, claiming her third win from four meetings against the Belgian.

The win was former top 10 player Kasatkina's fourth triumph over a top 20 player this year.

Kasatkina broke Mertens three times throughout the match, never dropping her own serve, sending down 4-2 aces.

Mertens was not helped by seven double faults throughout the match, with Kasatkina saving the Belgian's only break point.

Kasatkina will face American seventh seed Danielle Collins who was too good for Ana Konjuh. Collins only needed 52 minutes to win 6-0 6-2 over the Croatian qualifier.

Konjuh struggled on serve throughout, with Collins breaking her six times, while she only won one from 17 points on her second serve.

Top-seeded Elise Mertens rolled into the semi-finals at the Silicon Valley Classic with a 6-3 7-6 (10-8) win over Yulia Putintseva on Friday. 

The Belgian already has collected a pair of grand slam doubles titles this year at the Australian Open and Wimbledon and is seeking her seventh career singles crown. 

She will need to get past fourth seed Daria Kasatkina to have a chance. 

The Russian outlasted Magda Linette 6-4 3-6 6-4 in her quarter-final and is seeking her third title of 2021 after a three-year drought between wins. 

The other semi-final will match seventh seed Danielle Collins against qualifier Ana Konjuh.

Collins pulled out a tight 7-6 (7-5) 7-6 (7-4) upset of second seed Elena Rybakina to reach the semis in San Jose for the second time. 

The American won her eighth consecutive match after taking the title at Palermo two weeks ago. 

She will meet the only unseeded player remaining, Konjuh, who won the final 10 games of the match to close out Zhang Shuai 3-6 6-2 6-0. 

Top-seeded Elise Mertens pulled out a three-set win to reach the quarter-finals at the Silicon Valley Classic as all four matches went the distance on Thursday.

The Belgian, ranked 17th in the world, prevailed 6-2 4-6 6-4 over Kristina Mladenovic of France in two hours and 40 minutes to advance in San Jose.

She moves on to face the eighth seed, Yulia Putintseva, who rallied past Ajla Tomljanovic 3-6 7-5 6-3 as the Australian blew numerous chances to pull ahead by converting only two of 16 break-point opportunities.

In the bottom half of the draw, second seed Elena Rybakina remained on track with a 2-6 6-0 6-2 victory over American Claire Liu in a rematch of a second-round meeting at Wimbledon.

Rybakina next meets seventh seed Danielle Collins, a 3-6 6-4 6-3 winner over US countrywoman Sloane Stephens.

Stephens, the 2017 US Open champion, has slipped to number 67 in the world and was playing in her first tournament since Wimbledon as she prepares for a return to Flushing Meadows.

World number 26 Madison Keys was one of three seeded players to be eliminated in the second round of the Silicon Valley Classic in San Jose on Wednesday.

The American third seed was beaten by China's Zhang Shuai 7-5 7-6 (7-5) in one hour and 39 minutes.

Keys sent down 7-1 aces but Zhang, ranked 51st in the world, was excellent on return, converting four of her 11 break points.

Fourth seed Daria Kasatkina was also in danger after losing the first set but rallied to win 3-6 7-5 6-3 over France's Caroline Garcia.

"It was a tough match. From my point of view, I think the level of the game was very good, and I'm really happy that I was able to turn the match in the second set," Kasatkina said in the on-court interview.

Ninth seed Alison Riske was emphatically beaten by Croatian Ana Konjuh 6-1 6-4 in one hour and 13 minutes, while sixth seed Petra Martic bowed out to Poland's Magda Linette 7-5 7-6 (7-5).

Danielle Collins eased past Shelby Rogers 6-4 6-3 to book her spot in the second round at the Silicon Valley Classic on Tuesday.

World number 36 Collins proved too strong for American compatriot Rogers, winning in one hour and 25 minutes.

Collins will meet another American in the second round, with Sloane Stephens up next.

Former U.S. Open winner Stephens beat Caty McNally 6-4 6-2 earlier in the day.

Yulia Putintseva, meanwhile, eased her way into the second round with a 7-5 6-3 win over Croatian Donna Vekic.

Putintseva will face Australian Ajla Tomljanovic in the second round after she fought back to overcome Amanda Anisimova 1-6 7-5 7-5.

France's Kristina Mladenovic won 6-4 6-4 over Han Na-Lae, while American Claire Liu won in three sets against Dayana Yastremska.

Mladenovic will face top seed Elise Mertens, while Liu meets second seed Elena Rybakina.

Ninth seed Alison Riske defeated former top 10 player CoCo Vanderweghe in the opening round of the Silicon Valley Classic in straight sets on Monday.

Riske, who made the Wimbledon quarter-finals in 2019 and is currently ranked 37th in the world, won 6-3 6-4 in one hour and 28 minutes.

In a match which saw eight breaks converted, Riske's ability to win on her first serve proved the difference.

Vanderweghe, who made the Silicon Valley Classic finals in 2012 and 2017, was broken five times and won 58.1 per cent of first serve points.

Croatian sixth seed Petra Martic eased into the second round with a 6-3 6-3 victory over Anastasija Sevastova.

Martic will face Magda Linette next, after the Pole accounted for Dutch qualifier Lesley Kerkhove 6-3 6-3.

Ana Konjuh defeated Marie Bouzkova in a three-set epic which last two hours and 41 minutes, winning 7-5 3-6 7-5.

China's Zhang Shuai won over Emma Raducanu in straight sets, along with Carolina Garcia who defeated Emina Bektas.

Alexander Zverev followed up his stunning win over Novak Djokovic by storming to Olympic gold in the men's singles final.

A thumping 6-3 6-1 victory against Russian Olympic Committee's Karen Khachanov was the perfect way for world number five Zverev to land the biggest title of his career.

He won 10 of the last 11 games of his semi-final against world number one Djokovic and carried that form into Sunday's title match, brushing aside the threat across the net.

It makes him Germany's first men's singles champion at the Olympics. Steffi Graf won the women's title as part of a calendar Golden Slam in 1988, and four years later Boris Becker and Michael Stich teamed up to take doubles gold.

For the man who won the ATP Finals in 2018 and reached last year's US Open title match, this marked a step forward in a career many expect will eventually feature grand slam titles.

He secured a swift break in the first set against Khachanov, who was outstanding in the semi-finals against Pablo Carreno Busta but could not impose his game in the gold-medal match.

Another break followed and the set was gone in 43 minutes.

The second set rushed by in a mere 36 minutes, with Zverev against striking early and never looking back.

He created two break points in the second game of that set, and although Khachanov saved them, a third soon followed and the Russian netted on the forehand.

The momentum was all one way and there was never a moment when Khachanov, ranked 25th by the ATP, looked as though he might pose some danger. 

Zverev gave himself a first match point when he punched away a backhand volley, and the glory belonged to the German when Khachanov slapped a forehand into the net on the next point.

BENCIC DENIED GOLDEN DOUBLE

Belinda Bencic was the surprise champion in the women's singles and the Swiss had a chance to land a second gold medal on Sunday when she and Swiss partner Viktorija Golubic lined up in the doubles final.

It was not to be for Bencic and Golubic, however, as they were soundly beaten by the prolific Czech pair of Barbora Krejcikova and Katerina Siniakova.

A 7-5 6-1 win for the reigning French Open champions meant Bencic and Golubic were left with the silver medal.

But there was little in the way of regret for the Swiss pair, with Bencic showing off both her gold and silver medals after the match, saying: "We are overjoyed. We will fly back on Monday with other medallists. It's a great feeling to know people are waiting and they acknowledge the medals we won for our country.

"The week here was incredibly beautiful. We experienced so many emotions, and it's great to go back and share all of these emotions with everyone at home.

"It's not just about the medals or the titles, it's about the memories you create that will last forever. To share this with Viki is unbelievable.

"The whole week I never felt like I was in a normal tournament or playing alone. She was alongside me the entire way. I always tell her we won this gold medal together as well. When we will be 80 years old and have a coffee, we will talk about this moment and I cannot wait for that."

Ash Barty has conceded her dramatic Olympics mixed doubles defeat will be tough to take.

The world number one saw her hopes of winning a gold medal for Australia at Tokyo 2020 brought to an end on Friday.

Barty and partner John Peers won the first set against Russian Olympic Committee duo Andrey Rublev and Anastasia Pavlyuchenkova.

But Rublev and Pavlyuchenkova turned it around to win an epic clash 5-7 6-4 13-11 and reach the final.

With Barty already eliminated in the singles and women's doubles competitions, the best she can now hope for is a bronze medal alongside Peers.

They will meet Serbia's Novak Djokovic and Nina Stojanovic for the last spot on the podium.

"It is a tough one to swallow," said Barty. "I think those tie-breaks at times, they go either way and we just didn't quite have the run of the grain. 

"We put ourselves in a position to win the match, we just weren't able to close it out. It was a good level, no doubt disappointing."

Another chance at a medal means Wimbledon champion Barty will try to get over her loss swiftly.

She added: "But we get to fight for a medal - this one hurts but we still have an opportunity to play another match and try to win a medal for Australia. 

"We pick ourselves up pretty quickly, move on and know that we will give it our all and keep fighting right until the end.

"It's been quite a while since we've had an Australian medallist here [in tennis] at the Olympics so we're looking forward to that challenge."

In the men's doubles, Nikola Mektic and Mate Pavic are Olympic champions after they beat fellow Croatia representatives Marin Cilic and Ivan Dodig in the final.

Marketa Vondrousova landed another huge scalp in the form of Elina Svitolina to book her place in the gold medal match at Tokyo 2020 against Belinda Bencic.

It has been a memorable week for Vondrousova, who knocked out cauldron-lighter and "face of the games" Naomi Osaka in round three.

One more hurdle still stands in her way in the form of ninth seed Bencic, who fought hard for a three-set triumph over Elena Rybakina.

VONDROUSOVA MARVELS AGAIN

Vondrousova has had a Games to remember and she was a 6-3 6-1 winner against heavily fancied fourth seed Svitolina, becoming the first female Czech to reach an Olympic singles final in the process.

It means the Czech Republic will have a women's singles competitor on the podium for the second straight Games after Petra Kvitova finished with bronze at Rio 2016.

Incredibly, Vondrousova did not even automatically qualify for these Games with Karolina Pliskova, Barbora Krejcikova, Kvitova and Karolina Muchova ahead of her in the qualifying pecking order.

Vondrousova opted to use her protected ranking, dating back to a wrist injury prior to the pandemic, meaning Muchova missed out. Though criticised at the time, she is the last of the four remaining.

TEARS FOR BENCIC

Switzerland has a proud history of tennis stars but neither the legendary Roger Federer nor the great Martina Hingis have won Olympic gold in a singles event. Bencic has the chance to do that, though.

She had to go the distance against Rybakina in a 7-6 (7-2) 4-6 6-3 victory, with Bencic fighting back from 5-2 down in the first set.

Eventually Bencic came through in two hours and 44 minutes and the tears poured as she made the final.

"My emotions right now... it's too high," Bencic told the ITF website. "To have a medal, it's the greatest thing. Even to be here as an athlete, in the Olympics, it's amazing."

It means Switzerland will medal for the fourth straight Games with Federer, Stan Wawrinka, Hingis and the recently retired Timea Bacsinszky all having medalled.

The last Swiss gold medallist was at Barcelona 1992 where Marc Rosset won the men's singles.

Elsewhere, singles world number one Ash Barty remains in the hunt for mixed doubles gold. She and partner John Peers defeated Greek pair Stefanos Tsitsipas and Maria Sakkari – winning on a 10-point tie-break after the first two sets were shared.