Jessica Pegula got the better of Karolina Pliskova once again as she knocked the fourth seed out of the bett1open on Thursday.

The American beat the former world number one 7-5 6-2 in Berlin, setting up a quarter-final clash with Victoria Azarenka.

It is the fourth time this season Pegula has defeated Pliskova.

Azarenka was also a straight-sets winner, overcoming Angelique Kerber in a battling 6-3 7-5 victory.

The two-time Australian Open champion was 4-1 down in the second set but roared back to prevail over Kerber for the 10th time in 11 matches.

Garbine Muguruza enjoyed a 6-4 6-3 victory over Elena Rybakina and will take on Alize Cornet next, while Ludmilla Samsonova downed Veronika Kudermetova by the same scoreline and will now face Madison Keys.

Ashleigh Barty described her retirement from Thursday's second-round clash against Magda Linette at the French Open as "heartbreaking". 

Top seed Barty required medical attention during her first-round win over Bernarda Pera two days earlier, with a hip injury the cause for concern.

The 25-year-old – back at Roland Garros for the first time since winning her maiden grand slam title in Paris in 2019 – vowed to "play through the pain barrier", yet the injury prevented her from continuing when 1-6 2-2 down against her Polish opponent, who will face Ons Jabeur in the next round. 

The Australian's retirement throws the draw wide open, with both of the top seeds now out after Naomi Osaka decided to withdraw amid her disagreement with tournament organisers.

Barty's clay-court season ended with a title in Stuttgart, a runner-up finish in Madrid and an appearance in the quarter-finals in Rome, and she could scarcely hide her disappointment at the way things ended for her in the French capital. 

"It's heartbreaking," she told a media conference. "I mean, we have had such a brilliant clay-court season, and to get a little bit unlucky with timing and have something acute happen over the weekend and just kind of run out of time against the clock is disappointing. 

"It won't take away the brilliant three months that we have had, as much as it hurts right now.

"We did everything, absolutely everything we could to give myself a chance. It was a small miracle that we were able to get on court for that first round.

"I just tried to give myself a chance and see how it felt. Obviously practicing, we've had our restrictions and essentially tried to stay as fresh as possible and not aggravate it in any way, but in a match that's unavoidable at times.

"It got worse today and it was becoming at the stage where it was unsafe. As hard as it is, it had to be done. Right from the first game, I was battling the pain, and it just became too severe."

SVITOLINA CRUISES THROUGH, PLISKOVA DUMPED OUT

Fifth seed Elina Svitolina booked a third-round meeting with Barbora Krejcikova after seeing off Ann Li 6-0 6-4. 

Svitolina landed 74 per cent of her first serves and struck 10 winners to cruise past the American in the opening set. 

Li bounced back in the second, roaring into a 4-1 lead, but Svitolina clawed her way back to ensure she reached at least the third round in seven of her nine appearances at Roland Garros. 

Svitolina, who overturned a 2-5 deficit in the second set to beat Oceane Babel in the first round, said: "In the end, what I'm really happy with is the way that I was down in both matches in the second set and found a way. 

"I found a good level and didn't give up on the second set. That was a really good point for me, and I was really playing composed in both matches. It was two different players, but I was really happy that I could win in two sets in both matches."

Up next is Krejcikova, who overcame Ekaterina Alexandrova 6-2 6-3.

There is no place in the third round for ninth seed Karolina Pliskova, who was soundly beaten 7-5 6-1 by Sloane Stephens, while number 13 seed Jennifer Brady battled past Fiona Ferro 6-1 1-6 6-4. 

KENIN WINS BATTLE OF THE AMERICANS

Fourth seed Sofia Kenin defeated fellow American Hailey Baptiste, a qualifier who won four matches in Paris on her French Open debut, 7-5 6-3. 

Kenin will now face another compatriot in 28th seed Jessica Pegula, who beat Tereza Martincova 6-3 6-3.

Elsewhere, defending champion Iga Swiatek thumped Rebecca Peterson 6-1 6-1, Coco Gauff got the better of Wang Qiang 6-3 7-6 (7-1), and Elise Mertens edged out Zarina Diyas 6-4 2-6 6-4.

Ash Barty dramatically abandoned her Internazionali d'Italia quarter-final against Coco Gauff on Friday due to a right arm injury.

The world number one was leading 6-4 2-1 in Rome when, with her left thigh also heavily strapped, she pulled out of the match following talks with a trainer.

Barty's decision was precautionary as she will begin her French Open campaign in a little over two weeks' time, bidding to regain the title she won two years ago.

The scare came just hours after world number three Simona Halep announced she tore a calf muscle this week, putting the Romanian's Roland Garros prospects in some doubt.

Providing an update after the match with Gauff, which was interrupted by a rain delay, Australian Barty said: "The pain was becoming too severe so it was important to listen to my body and do the right thing knowing we have a slam."

Gauff, who had hit 12 winners to 15 unforced errors prior to her opponent's withdrawal, will now compete in her first career WTA 1000 semi-final.

Karolina Pliskova remained on course for a second Rome triumph in three years, after saving three match points to edge out Jelena Ostapenko.

The 2019 champion, who also finished runner-up last year, was 5-4 down in the final set when digging deep to hold off her 49th-ranked opponent.

The thrilling match went to a tie-break and Pliskova reeled off seven straight points after losing the opener to advance 4-6 7-5 7-6 (7-1).

"I'm just proud of how I fought," Pliskova said at her post-match news conference. "I'm happy that I stayed in there and fought until the end.

"We played last month, so I knew what was going to be happening. You can never get ready for some of the balls which she's playing."

Petra Martic stands between Pliskova and a place in the final for the third year running after the Croatian defeated Jessica Pegula 7-5 6-4.

Pegula eliminated Naomi Osaka earlier in the week but was second best against Martic, who progressed in one hour and 40 minutes.

Martic trailed 2-0 in the opening set before twice breaking Pegula to move 3-2 in front, but her opponent hit back to make it 5-5 in a tight contest.

However, Martic managed to break in the 11th game and served out the set, before showing her steeliness in the second to remain on course for a maiden WTA 1000 crown.  

Petra Kvitova recovered from a poor start to beat Magda Linette in the first round of the Internazionali BNL d'Italia on Monday.

Linette took just 31 minutes to win the first set in Rome, but world number 10 Kvitova responded superbly to win 1-6 6-0 6-2.

Two-time grand slam champion Kvitova racked up 16 unforced errors in the first set, yet rallied like the great competitor she has proved to be for so long to ensure she will face Vera Zvonareva - conqueror of Christina McHale - in the second round.

The 11th seed from the Czech Republic said: "The first set I started very badly. I was missing almost everything. On the court... [the ball] was bouncing everywhere as well. A little bit windy. I just had to get used to probably everything.

"The beginning of the second set when finally I held my serve and broke her serve, I think since then it was much, much better."

French Open champion Iga Swiatek advanced when Alison Riske retired at 5-4 down in the first set due to a recurrence of a left foot injury.

Swiatek, who will take on Sloane Stephens or Madison Keys in the second round, made 18 unforced errors but had won four games in a row from 4-1 down when the American was unable to continue. 

Coco Gauff battled past Yulia Putintseva 7-5 4-6 6-4 to set up a meeting with 17th seed Maria Sakkari  - who fended off qualifier Polona Hercog 7-6 (8-6) 3-6 6-2.

Amanda Anisimova will do battle with Elina Svitolina, a winner of this tournament twice, after defeating Wang Qiang 7-5 6-3. Jessie Pegula, Jennifer Brady and Petra Martic were among the other winners on day one.

Jessica Pegula said she "can't be more confident" after upsetting Elina Svitolina to reach her first grand slam quarter-final and Ash Barty stayed in the hunt for Australian Open glory on Monday.

Pegula, the daughter of NFL and NHL franchise owners of the Buffalo Bills and the Sabres, beat fifth seed Svitolina 6-3 3-6 6-3 on Rod Laver Arena to set up a showdown with her fellow American and friend Jennifer Brady.

Brady made it all the way to the semi-finals of the US Open last year and has now put together her best run at Melbourne Park after seeing off Donna Vekic 6-1 7-5.

World number one Barty has not dropped a set in her home major and started the second week by dispatching Shelby Rogers 6-3 6-4.

The top seed from Queensland's next assignment will be a meeting with Karolina Muchova, who saw the back of Elise Mertens 7-6 (7-5) 7-5.

Muchova, the 25th seed from the Czech Republic, has made it through to her second grand slam quarter-final - having also reached this stage at Wimbledon in 2019 - without losing a set.

Pegula to put friendship to one side

Pegula and Brady are close friends, but they will have to put that to one side when they meet in the quarter-finals.

The world number 61 claimed her first victory over an opponent ranked in the top 10 just over a month after Svitolina beat her in straight sets in Abu Dhabi.

Pegula hit 31 winners to Svitolina's 19 and won 21 points from 29 when she made a trip to the net as she broke new ground at a major

She said: "I can't get more confident, it's my best result yet and I'm playing good tennis. Today was a hard-fought win, so, yeah, feeling pretty good."

Pegula added on the prospect of facing Brady: "We're here to have fun and compete. If I can do it against somebody that I like, that I wouldn't mind if they beat me, hopefully not, but if they did, why not?"

Brady benefited from strict lockdown

Many players understandably struggled during and after being in a strict two-week lockdown in a hotel room following their arrival in Australia.

Brady was among the players who were not allowed out of their rooms for a fortnight, but said she used the situation to recharge her batteries before the first major of the year.

The 22nd-seeded Pennsylvanian said: "I think it was a little bit of a benefit for me, just taking a break from tennis. I had been going non-stop since World Team Tennis in June. I didn't take any time off.

"I was playing from June and then played US Open, the U.S. tournaments, and then went straight to Europe, then finished there and was training in Europe, then went home for Christmas and then came and started in Abu Dhabi.

"So obviously I didn't really feel super fresh mentally coming into Abu Dhabi. And then when I was away from tennis for two weeks, I felt like I wanted to play again to compete and I think that helped me."

Much improved Czech

Muchova had not been beyond the second round of the Australian Open before last week but now has a semi-final spot in her sights.

The 24-year-old was 4-0 down in the opening set as Mertens got off to a flyer but warmed to the task with her battling spirit and positive approach.

Muchova converted five of the six break points she earned on Margaret Court Arena, also coming from a mini-break down in a first-set tie-break.

She struck 25 winners to Mertens' 15 and advanced despite making 31 unforced errors, getting her rewards for throwing caution to the wind.

Ash Barty may have her focus on winning the Australian Open right now but suggested a career change could be on the cards in the future.  

The world number one made sure she will still be competing during the second week of the tournament in Melbourne by beating Ekaterina Alexandrova in straight sets.  

But, having played international cricket for Australia before switching to tennis, could the multi-talented Barty be considering trying another sport?  

Elsewhere in Saturday's action, Karolina Pliskova lost her cool – and also a couple of rackets – as she slipped to defeat against the impressive Karolina Muchova in an empty Rod Laver Arena, with fans not able to be present due to a five-day lockdown in the state of Victoria.

Elina Svitolina had no such problems in her third-round match, while Elise Mertens was victorious in just over an hour against Belinda Bencic. Jennifer Brady ended Slovenian qualifier Kaja Juvan's run in the first grand slam of the year.

AUSSIE RULES, OK? 

After winning 6-2 6-4 without ever needing to be at her peak, Barty was cheekily asked by former doubles partner Casey Dellacqua – now working in the media – whether she may be set to switch paths again, once her tennis career has come to an end.  

Australian rules football was the answer – but Dellacqua maybe got more than she bargained for from her former playing partner during the on-court interview. 

"I thought it was our deal, we're going to AFLW. It's ABCD [the nickname for the pairing from their doubles career]. We come as a package, and I know we will be going to the [Richmond] Tigers that is for sure," Barty said. "You can't go to Carlton. You have to come to the 'Tiges' with me."

Dellacqua replied: "I need to get out there and start practicing some kicking, but you are good. I would love to do that one day." 

For Barty, though, the next challenge facing her is Shelby Rogers, who knocked out 21st seed Anett Kontaveit during the evening session.  

MAKING A RACKET 

A disgruntled Pliskova was not impressed when punished for smashing up a racket during her match with compatriot Muchova. 

Having received a warning when throwing a racket to the floor during the course of the final game in the opening set, the sixth seed then vented her frustration again on another while in the players' tunnel.  

An official witnessed the incident and reported it to chair umpire Alison Hughes, who punished the Czech with a point penalty before she began serving to open the second set.  

"It's off court, I'm allowed to do what I want," Pliskova insisted when querying the decision to the official. She would go on to hold before recording two successive breaks, yet somehow failed to force a decider.  

Muchova rallied from 5-0 down in sensational fashion, winning seven games on the spin to triumph 7-5 7-5 to make it through to the last 16.

CONTRASTING PROGRESS FOR SEEDS

Svitolina has still yet to drop a set in the tournament after overcoming 26th seed Yulia Putintseva by a 6-4 6-0 scoreline.  

The fifth seed was twice down a break in the first set but, after eventually coming out on top to take a 1-0 lead, breezed through the second in a hurry.  

"She has a very different game style from what I played my last two rounds, so it wasn't easy at the beginning to adjust," Svitolina said. "As soon as I was feeling better, I just stepped my game, and it was quite a comfortable win after." 

Next up will be Jessica Pegula, who is through to the fourth round at a slam for the first time in her career after thrashing Kristina Mladenovic 6-2 6-1.  

There was also success for another American in the main draw, Brady defeating Juvan in straight sets. Her reward is a clash with Donna Vekic, the 28th seed having to save a match point before eventually seeing off Kaia Kanepi 5-7 7-6 (7-2) 6-4 after two hours and 38 minutes on court.