Coco Gauff described Serena Williams as "the reason why I play tennis" as she paid tribute to the soon-to-retire great, declaring: "There will never be another Serena."

Williams, a 23-time grand slam champion, announced in a piece in Vogue on Tuesday that she would soon retire.

The 40-year-old did not provide a firm date for the end of her career, but hinted that she could bow out after the US Open, which begins at the end of August.

Williams had won her first singles match in over a year on Monday at the Canadian Open, yet she wrote of the need to now prioritise her family.

And Gauff, playing at the same event in Toronto, was not short of praise for a legend of the sport.

"She's just been playing forever, my whole life," Gauff said after beating Madison Brengle.

"The legacy that she's left throughout her tennis career is something that I don't think any other player can probably touch.

"I think that the legacy that she'll continue to leave throughout her life is something that can inspire many more generations."

Gauff, a highly talented 18-year-old, has no interest in any tag as the 'next Serena', although she can take inspiration from Williams in dealing with such pressure.

"I've learned a lot from them [Serena and sister Venus]," Gauff said.

"People always tell me that you're going to be 'next whatever', blah, blah, blah, and Serena has been considered the GOAT [greatest of all time] for at least the second half of her career, and she never succumbed to that pressure.

"I think she overcame it, and I think that's something I take from her and try to learn from it. Not that I'm at her level and experiencing the same pressure she is, but in the moment I try to emulate that.

"For me, I grew up watching her. That's the reason why I play tennis, and tennis being a predominantly white sport, it definitely helped a lot, because I saw somebody who looked like me dominating the game, and it made me believe I could dominate, too.

"She's the GOAT. And undisputed, too, in my opinion. But I don't think that's an opinion, it's a fact.

"Serena, for me, is the GOAT. The GOAT of all GOATs. There will never be another Serena."

Coco Gauff shined on the opening day of the Canadian Open on Tuesday, defeating American compatriot Madison Brengle 6-1 6-3 to move to a record of 14-4 from her past 18 matches.

Gauff, who has not lost to anyone ranked lower than world number 22 Amanda Anisimova since the Australian Open, continued that impressive record by cruising past world number 62 Brengle, winning 58 per cent (34-of-59) of her return points in a dominant showing.

Anisimova, who eliminated Gauff from Wimbledon, also made it through her first match unscathed as she defeated hometown Canadian Carol Zhao 6-1 6-3.

China's Qinweng Zheng put another dagger into the Canadians with her 3-6 7-6 (7-5) 6-4 win over Rebecca Marino, but Bianca Andreescu gave the fans something to cheer for as she upset world number nine and winner of this past week's Silicon Valley Classic Daria Kasatkina 7-6 (7-5) 6-4.

Spain's Sara Sorribes Tormo prevailed against American Claire Liu 7-6 (7-4) 2-6 7-6 (7-5) in a three-and-a-half-hour battle of attrition, while Australian qualifier Ajla Tomljanovic upset world number 16 Veronika Kudermetova 6-4 2-6 7-6 (7-4) in two-and-a-half hours.

It was a disappointing showing from world number 10 Emma Raducanu as she went down 7-6 (7-0) 6-2 to the reigning champion of this event, Italy's Camila Giorgi.

Naomi Osaka also will need an early flight home after being forced to retire against Estonia's Kaia Kanepi, pulling the plug due to a persistent back injury while trailing 7-6 (7-4) 3-0.

In the late session, Olympic gold medalist Belinda Bencic successfully navigated the challenge of Tereza Martincova 6-4 6-2 to book a second round fixture against Serena Williams, and world number four Maria Sakkari survived a scare to finish strong and defeat Sloane Stephens 6-2 4-6 6-2.

Serena Williams' long and illustrious tennis career is drawing to a close after the American confirmed on Tuesday that the countdown has begun.

Following a long piece in Vogue, Williams wrote of her plan to "move in a different direction" after "these next few weeks", suggesting the US Open – which begins in late August – will be her last outing.

Thanks to her success and brilliance on the court, Williams has become synonymous with tennis and is regarded by many as the greatest the women's sport has ever seen.

Yet, her seemingly imminent retirement cannot be seen as a shock. At the age of 40, Williams has persisted with tennis far longer than most do, and that is testament to her quality and enduring desire for success.

With Williams now reaching the end, Stats Perform takes a look at the key facts, stats and figures of her career; in other words, Serena's remarkable legacy.

Twenty-three… and counting?

Of course, the headline fact for Williams' career is her grand slam titles count.

She has won 23, which is more than anyone else in the Open era.

But she's still got one target left: matching Margaret Court. The Australian's 24 grand slam successes include nine won before the Open era began in 1968, though her overall total has been the benchmark ever since she claimed her final crown at the US Open in 1975.

Clearly, victory for Williams at Flushing Meadows would be the perfect farewell.

The finals hurdle

Even if Williams only reaches the championship match next month, she'll still be equalling a different record.

Assuming she does compete in Queens, Williams heads into the US Open having played in 33 grand slam finals, one more than Martina Navratilova.

But Chris Evert (34) sits out in front, and that record will remain hers for many, many years if Williams cannot reach the finale at Flushing Meadows.

Top of the pile

It's been a while now since Williams was last the highest-ranked player in the world, but in a way that only further highlights how remarkable her career has been.

She's spent 319 weeks ranked as world number one, which is behind only Steffi Graf (377) and Navratilova (332).

While many might have expected Williams to have been top of the pile for even longer, it's worth remembering how she's spent time out due to injuries and pregnancy, with her general involvement in top-level tennis decreasing after 2014 when she played 16 tournaments – in 2016 that halved to eight, and during no year since has she played in more.

Additionally, some will also be surprised to learn she actually only finished the year as the top-ranked female player five times. Nevertheless, that's still third to only Graf (eight) and Navratilova (seven).

Go hard or go home

Such has been Williams' quality, she was always considered a threat regardless of the surface – she's won each grand slam at least three times.

But there's no denying she was at her most lethal on hard courts.

She has won 48 WTA Tour-level titles on hard courts, which is 11 more than anyone else (Graf) in the Open era.

Those 48 come from a grand total of 73 across all surfaces, leaving her ranked fifth behind Navratilova (167), Evert (157), Graf (107) and Court (92).

Surface to say…

Williams' comfort on hard courts goes even further than that.

She's won 539 matches on the surface, making her one of just two female players to surpass 500 victories on one specific ground type.

Navratilova (600 on carpet) is the only other player to achieve the feat, with Serena's sister Venus (498 on hard) the closest to the 23-time grand slam champion.

The grass is greener

Despite that unrivalled excellence, hard courts may not be the surface many feel to be most synonymous with Williams, however.

Wimbledon is the tournament that would appear to be her favourite.

She's reached the final at SW19 11 times. Only Navratilova can better that record for the most finals at one tournament – though it's worth saying she contested the WTA Finals and Chicago 14 times each, Eastbourne 13 times and 12 at Wimbledon.

Serena Williams, the most decorated tennis player in the open era, has hinted at retirement following the US Open.

One day on from winning her first singles match in 430 days at the Canadian Open, the legendary 23-time grand slam winner confirmed she is "evolving away" from the sport in an interview with Vogue Magazine.

Williams, who is one grand slam title away from matching Margaret Court's all-time record, appears set for one last shot at matching that haul at Flushing Meadows.

With Williams likely to call time on a spectacular career following one last outing at her home slam, below are 10 key quotes from her interview with Vogue.

THE KEY QUOTES

Reluctancy to step away 

"I've been reluctant to admit to myself or anyone else that I have to move on from playing tennis. Alexis, my husband, and I have hardly talked about it; it's like a taboo topic.

"It's like it's not real until you say it out loud. It comes up, I get an uncomfortable lump in my throat, and I start to cry. The only person I've really gone there with is my therapist."

Evolution

"I have never liked the word 'retirement'. It doesn't feel like a modern word to me. I've been thinking of this as a transition, but I want to be sensitive about how I use that word, which means something very specific and important to a community of people.

"Maybe the best word to describe what I'm up to is 'evolution'. I'm here to tell you that I'm evolving away from tennis, towards other things that are important to me."

No joy in reaching a "crossroads"

"Ashleigh Barty was number one in the world when she left the sport this March, and I believe she really felt ready to move on. Caroline Wozniacki, who is one of my best friends, felt a sense of relief when she retired in 2020.

"Praise to these people, but I'm going to be honest. There is no happiness in this topic for me. I know it's not the usual thing to say, but I feel a great deal of pain. 

"I hate it. I hate that I have to be at this crossroads. I keep saying to myself, I wish it could be easy for me, but it's not. I'm torn. I don't want it to be over, but at the same time I'm ready for what's next."

Family life key

"I never wanted to have to choose between tennis and a family. I don't think it's fair. If I were a guy, I wouldn't be writing this because I'd be out there playing and winning while my wife was doing the physical labour of expanding our family. 

"Maybe I'd be more of a Tom Brady if I had that opportunity. Don't get me wrong, I love being a woman, and I loved every second of being pregnant.

"A lot of people don't realise that I was two months pregnant when I won the Australian Open in 2017. But I'm turning 41 this month, and something's got to give."

Wanting Court's record 

"There are people who say I'm not the GOAT [greatest of all time] because I didn't pass Margaret Court's record of 24 grand slam titles, which she achieved before the open era that began in 1968. 

"I'd be lying if I said I didn't want that record. Obviously I do."

Pride in "extraordinary" record

"If I'm in a grand slam final, then yes, I am thinking about that record. Maybe I thought about it too much, and that didn't help. 

"The way I see it, I should have had 30-plus grand slams. I had my chances after coming back from giving birth.

"But I didn't get there. 'Shoulda, woulda, coulda'. I didn't show up the way I should have or could have. But I showed up 23 times, and that's fine. Actually it's extraordinary."

Tiger's advice 

"This spring, I had the itch to get back on the court for the first time in seven months. I was talking to Tiger Woods, who's a friend, and I told him I needed his advice on my tennis career. He was adamant that I be a beast, the same way he is!"

"Magical" Wimbledon return

"It felt magical to pick up a racket again. And I was good. I was really good. I went back and forth about whether to play Wimbledon, and the US Open after that."

"I don’t know if I will be ready to win New York, but I'm going to try."

"Unfortunately I wasn't ready to win Wimbledon this year. And I don't know if I will be ready to win New York. But I'm going to try. And the lead-up tournaments will be fun. 

"I know there's a fan fantasy that I might have tied Margaret that day in London, then maybe beat her record in New York, and then at the trophy ceremony say, 'See ya!' But I'm not looking for some ceremonial, final on-court moment."

Inspiring female athletes

"I'd like to think that thanks to me, women athletes can be themselves. They can play with aggression and pump their fists. 

"They can wear what they want and say what they want and kick butt and be proud of it all."

Serena Williams has revealed she is about to retire from tennis, announcing "the countdown has begun" with the US Open seemingly set to be her final tournament.

With 23 grand slam singles titles, Williams is the most decorated player of the Open Era, but her most recent major success came at the 2017 Australian Open.

The 40-year-old is one title shy of Margaret Court's all-time record and appears set for one last shot at matching the Australian.

Williams wrote on Tuesday of her plan to "move in a different direction" after "these next few weeks" following a long piece in Vogue.

She has already been named on the entry list for the US Open, which starts at Flushing Meadows at the end of August.

Posting an image of her interview on Instagram, Williams said: "There comes a time in life when we have to decide to move in a different direction.

"That time is always hard when you love something so much. My goodness do I enjoy tennis.

"But now, the countdown has begun. I have to focus on being a mom, my spiritual goals and finally discovering a different but just as exciting Serena.

"I'm just going to relish these next few weeks."

Within the Vogue piece, she added: "I'm turning 41 this month, and something's got to give.

"I have never liked the word retirement. It doesn't feel like a modern word to me.

"I've been thinking of this as a transition, but I want to be sensitive about how I use that word, which means something very specific and important to a community of people.

"Maybe the best word to describe what I'm up to is evolution. I'm here to tell you that I'm evolving away from tennis, toward other things that are important to me."

Williams wrote at length about the reasons for her decision, saying: "I started a family. I want to grow that family."

The American great had hinted at this decision on Monday following her defeat of Nuria Parrizas-Diaz at the Canadian Open.

That was Williams' first singles win in 430 days, and she said: "I guess there's just a light at the end of the tunnel.

"I don't know, I'm getting closer to the light, so… lately that's been it for me. I can't wait to get to that light."

When asked what "the light" means to her, Williams responded: "Freedom." She added: "I can't do this forever."

Serena Williams has revealed she is about to retire from tennis, announcing "the countdown has begun" with the US Open seemingly set to be her final tournament.

With 23 grand slam singles titles, Williams is the most decorated player of the Open Era, but her most recent major success came at the 2017 Australian Open.

The 40-year-old is one title shy of Margaret Court's all-time record and appears set for one last shot at matching the Australian.

In a long piece in Vogue, Williams wrote of her plan to "move in a different direction" after "these next few weeks".

Williams has already been named on the entry list for the US Open, which starts at Flushing Meadows at the end of August.

Serena Williams highlighted the first day of the Canadian Open, defeating Nuria Parrizas-Diaz 6-3 6-4 for her first win since the 2021 French Open.

In doing so, Williams became the fourth player since 2000 to win a WTA-level main draw match after turning 40, joining sister Venus Williams, as well as Kimiko Date Krumm and Martina Navratilova.

She also claimed the all-time record for wins at the Canadian Open, with 35, now one more than Chris Evert.

"I guess there’s just a light at the end of the tunnel," Williams said after the match. "I don’t know, I’m getting closer to the light. Lately that's been it for me. I can’t wait to get to that light."

She added: "I love playing though, so it’s like amazing. But I can’t do this forever. Sometimes you just want to try your best to enjoy the moments and do the best that you can."

Williams' older sister Venus, 42, was beaten on Monday by Swiss Jil Teichmann 6-2 6-3 with the match finshing after midnight following a delayed start due to rain.

One of the three seeded players in action on Monday, 15th seed Simona Halep had no issues cruising through the challenge of Donna Vekic 6-0 6-2.

It was similarly smooth sailing for 14th seed Karolina Pliskova in her all-Czech showdown against Barbora Krejcikova, winning 6-3 6-4, while Latvian 16th seed Jelena Ostapenko handled the challenge of Ukraine's Anhelina Kalinina 6-4 6-2.

Kazakhstan's Elena Rybakina defeated in-form qualifier Marie Bouzkova 7-5 6-7 (3-7) 6-1, likely earning a shot at Coco Gauff if the American wins as a heavy favourite tomorrow, while Brazil's Beatriz Haddad Maia beat Italy's Martina Trevisan 6-2 2-6 6-2 in a meeting of two top-30 players.

In a pair of all-American battles, Sloane Stephens edged Sofia Kenin 6-2 7-6 (7-5) 7-5, and world number 187 Asia Muhammad upset world number 25 Madison Keys in straight sets 7-6 (7-5) 6-4.

Alize Cornet defeated her French compatriot Caroline Garcia 3-6 6-3 6-3, and Canada's Katherine Sebov was unable to get the job done in front of her home fans, going down 6-3 2-6 5-7 to Yulia Putintseva.

In better news for the Canadians, Leylah Fernandez won 6-4 6-7 (2-7) 6-3 over Storm Sanders, while veteran two-time Wimbledon winner Petra Kvitova was beaten by Alison Riske 6-2 4-6 6-3.

Serena Williams thinks she is "getting closer" to the light at the end of the tunnel after winning her first singles match in 430 days at the Canadian Open on Monday.

The 23-time grand slam champion beat Nuria Parrizas-Diaz 6-3 6-4 in the opening round in Toronto, securing her first singles victory since a defeat of Danielle Collins at the 2021 French Open.

Williams returned from a one-year absence at Wimbledon last month after recovering from injury, but was beaten by Harmony Tan in the first round.

The long-awaited win in Toronto was her first since turning 40 and it gave the American a timely lift ahead of the US Open.

"I guess there’s just a light at the end of the tunnel," she said. “I don’t know, I’m getting closer to the light, so… lately that's been it for me. I can’t wait to get to that light."

When asked what "the light" means to her, she responded "freedom".

"I love playing though, so it’s like, amazing," she added. "But, you know, I can’t do this forever. 

"Sometimes you just want to try your best to enjoy the moments, and do the best that you can."

Williams became just the fourth player since 2000 to win a WTA-Tour level main-draw match after turning 40, along with Martina Navratilova, Kimiko Date-Krumm and her sister Venus Williams.

It also gave her the all-time lead for wins at the Canadian Open in the Open Era, this being her 35th victory at the event to break her tie with Chris Evert.

Serena Williams secured her first singles win since the 2021 French Open on Monday as she beat Nuria Parrizas-Diaz at the Toronto Open.

Also her first victory since turning 40, Williams looked impressive as she beat her Spanish opponent 6-3 6-4 in just under two hours.

She even earned a standing ovation when facing break point in the fourth game of the second set, as she worked hard to stay in the point before smashing a trademark forehand winner to save the game.

Williams, whose last grand slam title came in 2017 at the Australian Open, will face either number 12 seed Belinda Bencic or Tereza Martincova in the second round.

She is competing in the tournament as part of preparations for the US Open, and sealed her first win since splitting with coach Patrick Mouratoglou.

The duo had worked together for 10 years, before Mouratoglou revealed they had gone their separate ways in April after Williams decided not to compete at the French Open, with Mouratoglou moving on to train Simona Halep instead.

Williams returned to action after almost a year away from the game in the WTA event in Eastbourne in June in the women's doubles, before competing in the singles at Wimbledon, losing to Harmony Tan in an exciting first round contest on Centre Court at SW19

The 23-time grand slam champion has been named on the entry list for the US Open having pulled out of last year's tournament with a torn hamstring, entering with a protected ranking of 16.

Daria Kasatkina continued her strong season on Sunday by defeating American Shelby Rogers 6-7 (2-7) 6-1 6-2 in the final of the Silicon Valley Classic.

Russia's Kasatkina made her deepest grand slam run earlier this year by reaching the semi-final of the French Open, where she lost to world number one Iga Swiatek, and with this singles title – the fifth of her WTA career – she has claimed a career-best ranking of ninth in the world.

Against Rogers, the story was how the effectiveness of Kasatkina's serve continued to improve the further the match went on.

In the hard-fought opening set, Kasatkina won just 53 per cent (26-of-49) of her service points, allowing two breaks of serve and then flailing in the tie-break to drop five consecutive points.

Something changed from that point on, with Kasatkina improving to take 69 per cent (18-of-26) of her service points in the second frame, and that jumped again to 76 per cent (16-of-21) in the decider as she either figured something out, or Rogers ran out of steam.

Kasatkina did not allow a single break point opportunity after the first set, while converting four of her six chances to take a double-break in both the second and third.

Rogers had not lost a single set in her four matches to make it to the final, putting the exclamation point on a terrific run from Kasatkina that included wins over world number 27 Elena Rybakina, world number six Aryna Sabalenka and world number three Paula Badosa.

Liudmila Samsonova secured her second career singles title on the WTA Tour by defeating Kaia Kanepi in the final of the Citi Open.

Unseeded Russian Samsonova beat Estonian Kanepi 4-6 6-3 6-3 to take the title in Washington on Sunday.

It was Kanepi, the tournament's sixth seed, who struck first in a tight opening set with strong serving from both players, capitalising on the only break point opportunity in the 10th game.

While Samsonova won at least 70 per cent of her service points in each of the three sets, Kanepi's effectiveness dipped after the opener, with a 77 per cent (20-of-26) success rate in the first set, which dropped to 63 per cent (15-of-24) in the second and the third (12-of-19) to provide the Russian with an avenue back into the contest.

Kanepi led 3-2 in the second set, before Samsonova rattled off the next five games, securing a double break in the process and forcing a decider.

In a tight third frame, with Samsonova leading 4-3, she created three break point opportunities and only needed the first to grab a winning buffer, serving out the match for the title.

It is the 23-year-old's first singles title since her maiden victory at the German Open 14 months ago, and she only dropped two sets in the process while defeating fifth seed Elise Mertens, second seed Emma Raducanu, China's Wang Xiyu and Australia's Ajla Tomljanovic.

Shelby Rogers continued her dream run at the Silicon Valley Classic with victory over ninth seed Veronika Kudermetova securing a spot in the final against last year's runner-up Daria Kasatkina who toppled Paula Badosa.

Unseeded 29-year-old American Rogers has knocked off top seed Maria Sakkari along with Amanda Anisimova and 2019 US Open winner Bianca Andreescu on her way to the decider.

Rogers is also yet to drop a set, maintaining that run against the higher-ranked Kudermetova for a 6-3 6-4 victory in one hour and 20 minutes.

The triumph marks Rogers' biggest final in her career and her first on tour in six years.

Rogers, who trailed 2-0 in the second set, broke Kudermetova's serve with her second match point to clinch victory.

Second seed Badosa was bundled out by Kasatkina 6-2 6-4 in 46 minutes in the other semi-final on Saturday.

Badosa did not appear 100 per cent physically throughout the match and Kasatkina capitalised to secure back-to-back finals in San Jose.

The Spaniard had three break points in the decisive game before Kasatkina converted her first match point.

Kaia Kanepi and Liudmila Samsonova both powered their way into the Citi Open final with comfortable victories on Saturday.

Sixth seed Kanepi ruthlessly swept aside Australian Daria Saville 6-3 6-1 in one hour and 13 minutes, moving her closer to her fifth career title. The 37-year-old Estonian blasted 18 winners for the match.

World number 60 Samsonova proved too good for China's Wang Xiyu, winning 6-1 6-1 in one hour and seven minutes. Samsonova's big hitting was a key feature behind her win with four aces and 17 winners.

Despite being ranked fourth in the world, Paula Badosa came into her quarter-final showdown with the red-hot Coco Gauff as the underdog, but she played like a favourite en route to a 7-6 (7-4) 6-2 victory.

Usually one of her stronger weapons, Gauff's serve was a liability on Friday, with six double faults in the first set alone to drop the opening frame despite breaking Badosa twice.

In the second set, while Badosa was converting 92 per cent (11-of-12) of her accurate first serves into points, Gauff's figure was down at 53 per cent (eight-of-15) as the Spaniard's return game was at its best.

Badosa will meet seventh seed Daria Kasatkina in the semi-final after the Russian beat Belarus' Aryna Sabalenka 4-6 7-5 6-0. The longer the match went, the less effective Sabalenka became with her ability to return serve.

In the first set, which Sabalenka won, she was successful in 53 per cent (19-of-36) of the points against Kasatkina's serve, and that number plummeted to 14 per cent (two-of-14) in the decider.

Third seed and Wimbledon finalist Ons Jabeur was eliminated by ninth seed Veronika Kudermetova 7-6 (7-5) 6-2, and she will meet unseeded American Shelby Rogers in the second semi-final after she defeated Amanda Anisimova 6-4 6-4.

Meanwhile, in Washington at the Citi Open, Emma Raducanu felt the effects of her gruelling match 24 hours prior as she went down 7-6 (8-6) 6-1 to Liudmila Samsonova.

On Thursday, Raducanu played in the longest two-set match of the WTA season as she eventually made her way through two tiebreakers against Camila Osorio in two hours and 49 minutes, and she ran out of steam after another tough tie-break against Samsonova.

Samsonova will play China's Xiyu Wang in the semi-final after another upset, knocking out fourth seed Victoria Azarenka in convincing fashion 6-1 6-3.

Estonia's Kaia Kanepi booked her place in the second semi-final after a 6-7 (4-7) 6-4 6-3 win against Anna Kalinskaya, where she will meet Daria Saville after the Australian got the better of Canada's Rebecca Marino 6-1 7-5. 

Coco Gauff was too sharp with her return game for Naomi Osaka in the second round of the Silicon Valley Classic on Thursday, coming away with a 6-4 6-4 win.

Gauff – the world number 11 and tournament's sixth seed – created 12 break point opportunities in the match, while only allowing one for Osaka, despite eight double-faults.

Ultimately, Gauff won 41 per cent (29-of-71) of the points off Osaka's serve, while converting 85 per cent (28-of-33) of her successful first serves into points.

Earlier in the day in a major upset, top seed Maria Sakkari was eliminated in straight sets 6-1 6-3 by American Shelby Rogers. 

The world number three struggled with her serve throughout, landing only 45 per cent of her first serves, and winning just 52 per cent (12-of-23) of those points.

World number six Aryna Sabalenka needed three sets to defeat unseeded American Carolina Dolehide 5-7 6-1 7-5, and Russia's Veronika Kudermetova had less trouble dispatching Claire Liu 6-2 7-5 to set up an exciting match with Ons Jabeur in the quarter-final.

Meanwhile, in Washington at the Citi Open, Emma Raducanu played in the longest two-set match of the WTA season, defeating Camila Osorio 7-6 (7-5) 7-6 (7-4) in two hours and 49 minutes.

Both women created at least a dozen break point opportunities, with four total breaks each as the young British star battled blisters on her hands.

Raducanu will play Liudmila Samsonova after the Russian eliminated Australia's Ajla Tomljanovich 4-6 6-3 6-2.

In the last match of the day, China's Xiyu Wang got the better of Croatia's Donna Vekic 4-6 7-5 6-1, and she will meet the winner between Tereza Martincova and Victoria Azarenka in the quarter-final.

Second and third seeds Paula Badosa and Ons Jabeur eased into the Silicon Valley Classic quarter-finals on Wednesday, while Simona Halep and Jessica Pegula were bundled out of the Citi Open.

Last month's Wimbledon finalist Jabeur proved too good for American Madison Keys 7-5 6-1, winning in one hour and 22 minutes.

Jabeur, playing for the first time since Wimbledon, converted six of nine break points for the match, dominating the second set where she won 90.9 per cent first serve points.

Second seed Badosa survived a scare to win over qualifier Elizabeth Mandlik 6-2 5-7 7-6 (7-5) in two hours and 31 minutes.

Eighth seed Karolina Pliskova was knocked out by American Amanda Anisimova 3-6 7-5 6-1, while last year's runner-up Daria Kasatkina beat Taylor Townsend 6-4 6-0.

Two-time major winner Halep was forced to retire due to illness and top seed Jessica Pegula was bundled out by Daria Saville at the Citi Open.

In warm conditions, the 30-year-old Romanian battled throughout the match but eventually retired down 7-5 2-0 to Anna Kalinskaya after one hour and six minutes.

Halep had fought back from a 4-0 deficit in the first set to square it up at 5-5, before losing the first set.

However, the former world number one succumbed to illness early in the second set, handing Kalinskaya her passage into the quarter-finals.

On a dramatic day for the Citi Open favourites, world number seven Pegula was eliminated by Saville in straight sets in one hour and 38 minutes, 7-5 6-4.

Pegula was not helped by a first-serve percentage of 44.8 per cent, while she struggled to convert break points, with the Australian saving nine of 10 for the match.

Saville's win means she is 3-3 against top 20 opponents this year, progressing into the last eight where she will face Canadian qualifier Rebecca Marino.

Marino, who beat Venus Williams in her return to singles in the first round on Monday, knocked off Germany's Andrea Petkovic 6-3 3-6 6-1.

Estonian sixth seed Kaia Kanepi progressed into the quarters where she will face Kalinskaya after beating China's Zhu Lin 4-6 6-4 6-4.