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.

Camila Giorgi extended her strong run at the Viking International in Eastbourne as she dumped out top seed Aryna Sabalenka on Thursday.

The Italian had already beaten defending champion Karolina Pliskova en route to the last eight and pulled off another upset as she claimed a 7-6 (7-5) 0-6 6-4 win over Sabalenka.

Giorgi's bid for the third WTA Tour title of her career will now continue with a semi-final against Anett Kontaveit on Friday.

The Estonian also needed three sets to book her place, bouncing back from losing the opener to beat Viktorija Golubic 2-6 7-6 (7-2) 7-5.

Daria Kasatkina was unable to build on her win over fourth seed Iga Swiatek in the last round as she missed out on a spot in the semi-finals.

The Russian took the first set against Jelena Ostapenko but failed to build on that success as the Latvian ran out a 1-6 7-5 6-2 winner.

In the final match of the day, Anastasija Sevastova was beaten by Elena Rybakina, who had earned her place in the quarters by beating second seed Elina Svitolina the day before.

World number 61 Sevastova, who eliminated Coco Gauff, won the first set 6-2, but Rybakina fought back to claim the next two 7-6 (9-7) 7-6 (7-5).

Rainy conditions ensured there was no play at this week's other WTA event held in Bad Homburg, Germany, though one player was able to secure passage to the semi-finals.

Sara Sorribes Tormo claimed her place in the next round after Victoria Azarenka, her scheduled opponent, pulled out due to injury.

Second seed Elina Svitolina crashed out of the Viking International in Eastbourne at the last-16 stage on Wednesday with a straight sets defeat to Elena Rybakina.

The world number five lost 6-4 7-6 (7-3) to 21st-ranked Rybakina, whose reward is a meeting with Coco Gauff's conqueror Anastasija Sevastova in the quarter-finals.

Third seed Bianca Andreescu of Canada also lost in straight sets, Anett Kontaveit of Estonia beating her 6-3 6-3.

And it was the same story for fourth seed Iga Swiatek, though she at least took a set as she was beaten by Daria Kasatkina.

It took an impressive rally from Russia's Kasatkina to bounce back from losing the first en route to a 4-6 6-0 6-1 success.

She will now face Jelena Ostapenko, who beat Ons Jabeur 5-7 6-4 6-3.

In fact, top seed Aryna Sabalenka was the only seed to avoid a surprise exit on Wednesday as she cruised through.

The Belarussian, ranked fourth in the world, beat Alison Riske 6-1 6-4 in just over an hour to set up a clash with Camila Giorgi.

Giorgi had earlier followed up a win over defending champion Karolina Pliskova in the last round by beating Shelby Rogers 6-3 4-6 6-2.

There was no such string of shocks at Wednesday's other WTA event, the Bad Homburg Open in Germany, though first and second seeds Petra Kvitova and Victoria Azarenka needed three sets to progress.

Kvitova lost a second-set tie-break as she beat Ann Li 6-2 6-7 (4-7) 6-1 to reach the quarters, while Azarenka defeated Alize Cornet 6-4 3-6 7-6 (9-7).

Angelique Kerber, the fourth seed, progressed more smoothly, earning a comfortable 6-0 6-2 win over Russia's Anna Blinkova.

And Nadia Podoroska saw off the challenge of Patricia Maria Tig, winning 7-6 (7-4) 2-6 6-4.

Anastasia Pavlyuchenkova fought back to win a pulsating French Open battle with her doubles partner Elena Rybakina and reach an elusive first grand slam semi-final.

A decade after playing in the last eight of a major for the first time at Roland Garros, Pavlyuchenkova finally broke new ground with a hard-fought 6-7 (2-7) 6-2 9-7 victory on Tuesday.

The 29-year-old had lost six grand slam singles quarter-finals but the 31st seed will do battle with surprise package Tamara Zidansek for a place in the championship match in Paris.

Rybakina beat the great Serena Williams to reach the last eight and gave another demonstration of her huge promise, but made 43 unforced errors in an entertaining contest that took two hours and 33 minutes to settle on Court Philippe-Chatrier.

After Kazakh Rybakina claimed the first break for a 3-1 first-set lead with clean striking off both wings, Pavlyuchenkova took a more aggressive approach and that paid off when she got back on serve at 4-3.

Rybakina, the 21st seed, took that setback in her stride, storming into a 5-0 lead after a tactical first-set battle was taken to a tie-break, which ended with Pavlyuchenkova putting a backhand into the net.

Pavlyuchenkova appeared to have missed out on a fourth chance to break in a long sixth game of the second set when she slipped, but looked up while she was sitting on the clay to discover Rybakina had made a mess of a simple smash.

The 29-year-old broke again to wrap up the set and maintained her momentum in the decider, charging into a 2-0 lead - with her backhand firing.

They were back on serve at 4-4 with the nerves jangling following four breaks in five games, both players looking understandably tense but still producing some high-quality tennis.

It was Pavlyuchenkova who claimed the decisive fifth break of a long final set to advance, earning a match point with a rasping forehand winner before her young opponent double-faulted.

Data Slam: A half-century to remember for Pavlyuchenkova

Pavlyuchenkova is making her 50th grand slam main draw appearance and she has marked it with her best run. More proof that persistence pays off.

WINNERS/UNFORCED ERRORS

Pavlyuchenkova – 44/28
Rybakina – 46/43

ACES/DOUBLE FAULTS

Pavlyuchenkova – 5/2
Rybakina – 5/6

BREAK POINTS WON

Pavlyuchenkova– 6/17
Rybakina – 3/7

Serena Williams crashed out of the French Open in the fourth round as 21st seed Elena Rybakina sealed a stunning 6-3 7-5 victory on Sunday.

Rybakina, representing Kazakhstan, had not previously been past the second round at Roland Garros but she is enjoying a strong run this fortnight and showed no nerves against her illustrious opponent, hitting a series of impressive winners that the 39-year-old Williams could not match.

After breaking back and then moving 5-4 ahead in the second set, it seemed 23-time grand slam champion Williams might take the match to a decider, but Rybakina reeled off the next three games to seal the biggest win of her career and set up a quarter-final clash against Anastasia Pavlyuchenkova. 

Rybakina started in a confident mood, winning her first two service games without dropping a point.

Williams came under intense pressure on her second service game, with Rybakina breaking and opening up a 3-1 lead when the American sent a backhand long.

Williams broke back in the seventh game of the match, but she squandered the opportunity to pull level when Rybakina broke again in the next game.

A nervy Rybakina needed four set points to win the opener 6-3, sealing it in 36 minutes when Williams flashed a cross-court backhand long.

Williams found herself in more trouble at the start of the second set, Rybakina comfortably breaking to move 1-0 up, but the three-time Roland Garros champion restored parity in the next game with four consecutive winners.

Rybakina missed a golden opportunity to set up a break point in the fifth match of the second set, sending a backhand long with Williams out of position, the American surviving to serve out the game and move 3-2 up.

The 21-year-old won the next game with an ace, setting the stage for her to break Williams and move 4-3 ahead.

Williams roared back, though, winning the next two games to leave Rybakina serving to stay in the set.

Not only did she do that, but she won the next two games as well to put the seal on a memorable victory that took one hour and 19 minutes.

DATA SLAM: RYBAKINA PUNISHES SLOPPY WILLIAMS

Williams looked well off the pace against an opponent who certainly made the most of her first appearance in the fourth round of a grand slam tournament. Williams won just 59 per cent of the points from her first serve, compared to Rybakina's 69 per cent, while the Russian-born player won 86 per cent of points at the net compared to Williams' 50 per cent.

WINNERS/UNFORCED ERRORS

Williams – 15/19
Rybakina – 21/13

ACES/DOUBLE FAULTS

Williams – 2/1
Rybakina – 4/4

BREAK POINTS WON

Williams – 3/5
Rybakina – 5/7