Ashleigh Barty acknowledged it will be a "tough" week for her at the French Open as she plans to play through the pain at Roland Garros.

Barty – champion in Paris back in 2019 – had to take a medical time out during her first-round tie with Bernarda Pera on Tuesday.

The Australian world number one struggled with a hip issue, yet still progressed with a 6-4 3-6 6-2 win.

"It's going to be a little bit tough this week. I think over the weekend we had a bit of a flare-up through my left hip, which obviously just needed a bit of help today, needed some assistance to try and release it off as best I could," the 25-year-old said in her post-match news conference.

"I'm not going to hide behind the fact I'm not quite 100 per cent but I can guarantee that I will go out there with the right attitude every day and be really accepting of that and give it a crack no matter what.

"We're confident in that we can get my body to a point where I'm able to compete. We're here, we're fighting, we're in with a chance, and that's all we can do."

Magda Linette is next up for Barty on Thursday, the Polish player defeating Chloe Paquet in straight sets.

COCO CARRIES ON HER FORM AS SEEDS REACH ROUND TWO

Fresh from her triumph in both the singles and doubles in Parma, and a run to the Internazionali BNL d'Italia semi-finals, Coco Gauff started her campaign with a tough win over qualifier Aleksandra Krunic.

Gauff, the 24th seed, certainly had to do it the hard way, with the 17-year-old clawing back four set points in the opener, but some brilliant first serves – she landed 71 per cent of them – got her through in straight sets.

It brought up Gauff's first win at a grand slam as a seed. She is ranked at 25th in the world, making her the youngest American woman to make it into the top 25 since Serena Williams in 1998. 

Wang Qiang will face Gauff in round two in what is a repeat of the Parma final.

Meanwhile, three other big names also made it through. Former world number one and 2017 French Open semi-finalist Karolina Pliskova overcame her close friend Donna Vekic 7-5 6-4, while fellow Czech Karolina Muchova came from behind to beat Andrea Petkovic 1-6 6-3 6-4.

With Petkovic's exit, there are no female players from Germany in the second round at Roland Garros for the first time since 1958.

Fifth seed Elina Svitolina is also through to round two after coming back from a break down in the second set to beat teenager Oceane Babel 6-2 7-5.

"It's a first time for her to play here in the main draw of the grand slam and to face the sixth player in the world it's extremely tough," Svitolina said of her young opponent.

"I think she dealt very well with it and she went for her shots in the second set and made life very difficult for me."

SUAREZ NAVARRO MAKES COMEBACK

Carla Suarez Navarro overcame Hodgkin lymphoma earlier this year, after revealing last September that she had been diagnosed with the rare cancer.

Suarez Navarro won that battle and is now cancer free, but in what she said will be her last appearance at Roland Garros, she slipped to a defeat to 2018 finalist Sloane Stephens.

The Spaniard took the first set 6-3 and forced a tiebreaker in the second, but it was Stephens who edged it before taking that momentum into the decider to claim a 3-6 7-6 (7-4) 6-4 win.

Naomi Osaka's shock withdrawal from the French Open generated an outpouring of support across the tennis world and beyond. 

The four-time grand slam winner pulled out of Roland Garros on Monday, a day after tournament organisers said her continued refusal to attend mandatory press conferences could result in her being thrown out of the event.

Osaka said in a statement posted to social media that she has had bouts of depression since winning the US Open in 2018 and never intended for her stance to become a distraction. 

Monday's action in Paris had mostly been completed when the news broke, but Serena Williams shared her thoughts following an evening match. 

Williams acknowledged feeling anxious dealing with the press at times early in her career, but said she believed the experience made her stronger. 

Top of mind, however, was concern for Osaka. 

"The only thing I feel is that I feel for Naomi. I feel like I wish I could give her a hug because I know what it's like," Williams said.

"We have different personalities, and people are different. Not everyone is the same. Everyone is different and everyone handles things differently.

"You just have to let her handle it the way she wants to, in the best way she thinks she can, and that's the only thing I can say. I think she's doing the best that she can."

Osaka's fellow players and others took to social media with encouraging messages for the 23-year-old. 

Venus Williams wrote on Instagram: "So proud of you. Take care of yourself and see you back winning soon!"

Young American star Coco Gauff responded to Osaka's tweet by writing "stay strong ... I admire your vulnerability." 

A pair of tennis legends also weighed in on Twitter. 

"I am so sad about Naomi Osaka. I truly hope she will be ok," Martina Navratilova wrote.

"As athletes we are taught to take care of our body, and perhaps the mental and emotional aspect gets short shrift.

"This is about more than doing or not doing a press conference. Good luck Naomi - we are all pulling for you!"

Billie Jean King added: "It’s incredibly brave that Naomi Osaka has revealed her truth about her struggle with depression. Right now, the important thing is that we give her the space and time she needs. We wish her well."

Mardy Fish, the former ATP player who reached number seven in the world, wrote to Osaka: "Mental health is nothing to criticise. Nothing to joke about. Pls [sic] take your mental health seriously. Without my support system, I truly believe I would not be here today. Here for you."

That public show of support extended beyond tennis, as prominent NFL and NBA players praised Osaka for her courage. 

"We are with you," said Seattle Seahawks quarterback Russell Wilson.

NBA star Stephen Curry wrote: "You shouldn't ever have to make a decison like this - but so damn impressive taking the high road when the powers that be don't protect their own. Major respect."

Coco Gauff was in superb form as she dispatched Wang Qiang 6-1 6-3 to win the Emilia-Romagna Open, the teenager's second career title.

Third seed Gauff needed just 74 minutes to seal a straight sets success, with her Chinese opponent unable to lay a glove on her.

The 17-year-old, who had previously won the 2019 Linz Open, enjoyed a run to the semi-finals at the Internazionali BNL d'Italia last week and looks in fine fettle heading to the French Open.

She dropped only one set during her charge at Parma, a triumph which takes her into the top 30 in the WTA rankings and ensures that she will be seeded for the French Open.

Gauff had won 19 of her last 25 WTA Tour matches heading into Saturday's contest, and had little trouble in making it 20.

A brief rally from Wang at the end of the start of the first set was not enough to stop Gauff, who saved all four of the break points she faced throughout the contest.

She now has the chance to complete a clean sweep in Parma, as she pairs with Caty McNally in the doubles final, against Darija Jurak and Andreja Klepac.

Coco Gauff battled through to the second WTA final of her burgeoning career as the 17-year-old American sank the title hopes of Katerina Siniakova in Parma.

At the Emilia-Romagna Open, Gauff scored a 7-5 1-6 6-2 victory over the player who shocked top seed Serena Williams in round two of the clay-court tournament.

It means Gauff faces a first final appearance since landing the Linz Open title as a 15-year-old in October 2019, with Wang Qiang awaiting her in the title match after a dramatic win over former US Open champion Sloane Stephens.

Gauff served eight double faults against Siniakova, a familiar weakness in her game, but her opponent was similarly afflicted and coughed up 10 doubles across the two hours and eight minutes of their contest.

Having reached the semi-finals of the WTA 1000 event in Rome last week, Gauff is enjoying her stay in Italy ahead of competing at the French Open.

"I need to play more aggressive. I learned to trust my shots and they ended up working out," she said on Amazon Prime. "The Italians, they cheer me on and bring me good luck, and hopefully I can keep this going tomorrow."

Wang beat Stephens 6-2 7-6 (7-3), but the scoreline barely told the story of the second semi-final. It seemed sure to go to a third set as Stephens raced to a 5-1 lead in the second, but Wang reeled her in before easing through the tie-break.

Chinese star Wang, coached by former Wimbledon champion Pat Cash, said: "I just tried to hang in there and focus on the court, try to hit every ball back. It will be my first time to play [Gauff] and I will make a plan tonight."

At the Serbia Open, promising Colombian teenager Maria Camila Osorio Serrano set up a semi-final against Croatian Ana Konjuh by beating world number 50 Aliaksandra Sasnovich.

Osorio Serrano secured a 6-4 6-2 success, while Konjuh saw off Argentinian Nadia Podoroska 6-4 6-3. In the top half of the quarter-final draw, Spain's Paula Badosa was a 6-2 6-4 victor over Swedish player Rebecca Peterson, and Bulgarian Viktoriya Tomova edged out Hungarian Reka-Luca Jani 6-1 2-6 7-5.

Coco Gauff continued her fine form with a 6-3 6-3 quarter-final triumph over fellow American Amanda Anisimova at the Emilia-Romagna Open.

In a contest between two teenage stars, it was 17-year-old Gauff who sealed her second semi-final spot in as many weeks, having made the last four at the Internazionali d'Italia.

Third seed Gauff will face Katerina Siniakova next, after the Czech followed up her win over Serena Williams with a 7-5 6-1 defeat of Caroline Garcia.

"I was pretty satisfied with the way I played," Gauff said, after fending off Anisimova.

"I do think I could have served a little bit better, but other than that, I was pretty happy with the way I played."

Despite her valid concerns, Gauff won 72 per cent of points after landing her first serve and forced six breaks to win in style, reeling off six games on the trot from 3-0 behind in the second set.

The other semi-final will see second seed Wang Qiang take on Sloane Stephens.

Wang prevailed 7-6 (7-4) 3-6 7-5 against Petra Martic, while Stephens saw off Sara Errani 6-3 6-0.

It was another rain-affected day at the Serbia Open, where Maria Camila Osorio Serrano managed to get past Kamilla Rakhimova 4-6 6-3 6-4.

Anna Kalinskaya and Reka Luca Jani were locked at one set apiece in the only other match to get started before the weather halted play.

Seeds Petra Martic and Coco Gauff were victorious at the Emilia-Romagna Open on Wednesday, but injury cut short Sara Sorribes Tormo's run in the tournament.

Gauff recorded five breaks of serve as she overcame Italian Camila Giorgi in routine fashion, a 6-2 6-3 triumph securing the third seed a place in the quarter-finals.

The American did have a few issues on her own serve, leading to seven double faults, but ended up winning in one hour and 11 minutes.

Martic, the second seed at the event, was made to work in the first set of her match against Ludmilla Samsonova, both players saving a break point on serve as it went the distance.

There was little to split the pair in the tie-breaker too, Martic edging it 7-5 as she capitalised on her first opportunity to take the set.

The second was more straightforward for the Croatian, an early beak of serve putting her in front before she repeated the trick to wrap up victory in the ninth game.

There were wins in straight sets for fellow seeds Caroline Garcia and Wang Qiang too, as they defeated Anna-Lena Friedsam and Martina Di Giuseppe respectively.

For Garcia, the triumph means a first quarter-final appearance in the 2021 season.

Sorribes Tormo was the only seeded player to exit in the day’s action, the Spaniard forced to retire at 2-2 in the deciding set against Sara Errani due to a problem with her left thigh.

"I'm very sorry for Sara. It was a battle, I know every time we play together it is like this. I was mentally ready to fight, to suffer," Errani said in her on-court interview.

Top seed Serena Williams is already out, beaten in straight sets by Katerina Siniakova to deal the 23-time grand slam champion a further blow ahead of this year's French Open.

Serena Williams saw her hopes of an extended run at the Emilia-Romagna Open come to an early end on Tuesday, the top seed succumbing to Katerina Siniakova in straight sets.

Williams had taken up a wildcard to play in the tournament following an early exit in Rome, where she was beaten by Nadia Podoroska in her opening contest in the clay-court swing.

Her campaign in Parma got off to a better start on Monday, a 6-3 6-2 result against WTA Tour debutant Lisa Pigato bringing a first triumph since losing in the semi-finals of the Australian Open in February.

However, the 23-time grand slam champion was unable to repel a determined Siniakova as she slipped out at the last-16 stage.

"It was a fantastic match and I played so well, I'm so happy that I could finish like that," Siniakova said after recording a 7-6 (7-4) 6-2 result.

"It was a pleasure to share the court with her.

"Now I will have the pressure because I defeated a great player, but I will enjoy it. I'm happy that I can continue and I will try to play my best in the next match."

Having failed to convert a set point opportunity, Williams hit back after losing serve with a break of her own to force a tie-break in the opener.

But Siniakova forced her way into a 5-3 lead before sealing it with a service winner, then quickly seized control of proceedings in a second set which was far less competitive.

Third seed Coco Gauff came through two tie-breaks to see off Kaia Kanepi, the American teenager having let slip a 5-1 lead in the second set before eventually sealing a 7-6 (8-6) 7-6 (9-7) win.

Petra Martic had no such issues in her opening contest against Varvara Gracheva, the second seed easing through 6-4 6-2 after one hour and 21 minutes on court.

French Open champion Iga Swiatek beat Elina Svitolina and Coco Gauff on a hectic Saturday to set up a clash with Karolina Pliskova in the Internazionali d'Italia final.

The Polish teenager began her day with a 6-2 7-5 morning victory over fifth seed Svitolina, twice a winner of this tournament in Rome.

It was a match that was carried over from Friday's schedule after rain interrupted play, and Swiatek delivered a convincing performance.

That set up the semi-final clash with Gauff, the 17-year-old American who was competing at this stage of a WTA 1000 event for the first time, having been gifted her last-four place when Ash Barty abandoned their quarter-final match due to injury on Friday.

There was no sign of fatigue from Swiatek as the 19-year-old powered to a 7-6 (7-3) 6-3 victory in a battle of the leading teenage stars of the women's game, who faced each for the first time in what could be a long rivalry.

Swiatek said: "I felt really good today. It's a big difference between my previous matches and today. I was able to beat Elina, so that shows that my game is here, I'm ready for anyone. It gave me a real confidence boost."

Quoted on the WTA website, the 15th seed added: "It's always hard to play against a young superstar, especially when I'm not used to that because I was always the youngest one.

"I just tried to have a high level of energy, even though it was my second match."

Between her two matches, Swiatek would have learned it was Pliskova waiting in the final, as the Czech ninth seed defeated Croatian Petra Martic 6-1 3-6 6-2 to keep up her remarkable record in the Italian capital.

Pliskova won the Rome title in 2019 and was runner-up to Simona Halep last year, but the 29-year-old former world number one has not been to a final since this event unusually took place in September of last year, having been delayed due to the pandemic.

Swiatek won as a major outsider at Roland Garros in October, defying her world ranking which at the time was a lowly 54th, and will face, in Pliskova, a player who has yet to win a grand slam title, a glaring absence amid an otherwise stellar career.

Against Gauff, Swiatek made 25 winners and just 16 unforced errors, a healthy ratio, and took three of her four break-point opportunities.

She sealed victory on a third match point, a big backhand forcing a stretching Gauff to chip beyond the baseline.

Gauff hit seven aces but also five double faults and had 33 winners and 32 unforced errors in the contest.

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.  

Ash Barty will meet Coco Gauff in the quarter-finals of the Internazionali BNL d'Italia after an impressive defeat of Veronika Kudermetova.

The world number one claimed her 27th Tour-level win of this year, seeing off Kudermetova 6-3 6-3 in 81 minutes to reach the last eight in Rome for the first time.

Barty admitted it took some time to get used to the "wow factor" of centre court in the Italian capital, but she rarely looked under threat as she moved to 13-2 on clay in 2021.

The Australian would have faced Aryna Sabalenka for the third tournament in a row had it not been for a sterling performance from Gauff, who won 7-5 6-3 to secure a fourth quarter-final this year.

"Coco has shown that she loves to bring her best tennis against the players that challenge her the most," said Barty, who has never played against the American teenager. "She's played an exceptional tournament thus far. She's got the ability to take the game on. She's aggressive, she can run, she can trust her legs.

"I think it's going to be important for me to try to get the match back on my terms as often as possible. I know when they're in her patterns, the way she likes to play, she's extremely dangerous and very good at what she does. I think it's going to be a new challenge, a clean slate for both of us."

Matters were more difficult for reigning French Open champion Iga Swiatek, who saved two match points before beating Barbora Krejcikova 3-6 7-6 (7-5) 7-5 in a contest lasting nearly three hours.

Powerful serving from Krejcikova and some errant shots from Swiatek gifted the Czech the chance to serve out a straight-sets win, but Swiatek held firm before taking the tie-break.

Swiatek persisted with a drop shot that seemed to cause difficulties for her and her opponent before Krejcikova's aim went awry at the end of the decider.

"I had fun when I played drop shots because today I felt them really good," said Swiatek, who will now face fifth seed Elina Svitolina after her 6-4 6-2 beating of Garbine Muguruza.

"I asked myself a question, what would annoy me in that situation? So, I tried to do that. So, yeah, sometimes it didn't look pretty, but I'm happy that I could do that. One year ago I wouldn't even come up with a solution like that. That's a progress."

Jessica Pegula followed up her shock win over Naomi Osaka by defeating Ekaterina Alexandrova in straight sets. She will now face Petra Martic, who came from a set down to defeat world number 44 Nadia Podoroska – conqueror of Serena Williams on Wednesday.

Ninth seed Karolina Pliskova, who beat Vera Zvonareva 7-5 6-3, will face Jelena Ostapenko following her three-set defeat of Angelique Kerber.

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.

Ash Barty won her first match on clay since reigning supreme at the 2019 French Open as the world number one rolled into the Volvo Car Open round of 16.

Barty – who last featured in a clay-court match en route to Roland Garros glory almost two years ago amid the coronavirus pandemic – made light work of Misaki Doi 6-2 6-1.

Miami Open champion last week, top seed Barty continued where she left off at the WTA 500 event on Wednesday, closing out proceedings in just over an hour in Charleston.

"I had to use it as an opportunity to try and build some comfort," Barty said. "I think having a couple days between Miami and playing this first match was important, to have my body rest, but to also try and prepare to change surfaces. It was a very quick turnaround, but I felt great out there tonight."

Barty – who now boasts a 15-2 win-loss record in 2021 – will next face Shelby Rogers after she outlasted 13th seed Amanda Anisimova 1-6 7-5 6-4.

As for second seed Sofia Kenin, the 2020 Australian Open champion slumped to a shock 4-6 6-3 6-4 defeat against Lauren Davis midweek.

World number four Kenin – runner-up at last year's French Open – eased to the first set but fellow American Davis, ranked 79th in the world, changed tactics to fine effect.

"I was a bit uncomfortable so I just really dug deep and really started to think about how to beat her and I found that heavy deep balls were not her favourite," the 27-year-old Davis said.

"Being on clay, the ball bounces high, pushing girls back, so it's very effective."

Kenin took a medical timeout at 3-0 down in the deciding set but, despite reeling off the next three games, she was unable to see Davis off as her 2021 woes continue.

Davis now heads into another all-American clash with teenage sensation Coco Gauff – who came from 1-3 down in the third to defeat Liudmila Samsonova 4-6 6-1 6-4 in an absorbing two-hour contest.

Belinda Bencic – the fifth seed – crashed out as Paula Badosa claimed the first top-20 win of her career following a 6-2 6-7 (2-7) 6-1 success.

Badosa will face Caty McNally in the last 16 after the 19-year-old American beat Anastasija Sevastova 7-6 (7-3) 2-6 6-4.

Seventh seed Elise Mertens was another big name to depart as Alize Cornet prevailed 7-5 6-3, although 15th seed Veronika Kudermetova and 12th seed Ons Jabeur progressed in with the minimum of fuss.

Former US Open champion Sloane Stephens, meanwhile, topped eighth seed Madison Keys 6-4 6-4.

Seeds were even more vulnerable at the Copa Colsanitas in Bogata, including the top-seeded Saisai Zheng who was dispatched 6-4 6-1 by Stefanie Voegele.

Zheng's compatriot Yafan Wang, seeded eighth, went down 6-3 6-3 to Viktoriya Tomova.

Arantxa Rus and Jasmine Paolini, the third and sixth seeds respectively, lost in three to Spanish duo Nuria Parrizas Diaz and Lara Arruabarrena.

Garbine Muguruza continued her superb start to 2021 as the former world number one won a WTA Tour-leading 21st match of the season to progress at the Volvo Car Open.

Muguruza – the sixth seed in Charleston – dispatched qualifier Magdalena Frech 6-1 6-3 in her first match of the clay court season on Tuesday.

Two-time grand slam champion Muguruza has already reached three finals this year, winning once in Dubai, and took just 70 minutes to overcome Fech on her return to Charleston following an eight-year absence. 

"I'm happy that I got this win, that I fought hard, that I kept my fighting spirit through the whole match, also in the second set which was tighter than the first set," Muguruza told reporters, in quotes reported on the WTA's official website.

Joining Muguruza in the round of 16 is third seed and fellow former grand slam champion Petra Kvitova, who saw off Storm Sanders 7-6 (7-4) 6-2 in her first-ever match at the WTA Premier tournament. 

Meanwhile, two former Charleston champions will go head-to-head after Sloane Stephens – a winner in 2016 – beat lucky loser Xinyu Wang 6-2 6-4 to tee up a second-round tie with 2019 victor Madison Keys.

Shelby Rogers took advantage of being in familiar surroundings by seeing off Kristina Mladenovic, while Monterrey Open champion Leylah Fernandez also progressed at the expense of 16th seed Shuai Zhang.

As for American sensation Coco Gauff, the 14th seed beat Tsvetana Pironkova 6-3 6-0 en route to the last 32.

There was a first-round surprise at the Colsanitas Cup in Bogota, where second seed Sara Sorribes Tormo was upstaged by 2012 French Open runner-up Sara Errani 7-5 7-5.

Colombian youngster Maria Camila Osorio got the better of American Sachia Vickery 6-3 6-2, with a potential top-100 scalp of Tereza Martincova next in her sights.

Elise Mertens came from behind to clinch a semi-final spot at the Dubai Tennis Championships but Coco Gauff bowed out on Thursday.

Mertens said she "just didn't want to let go" after coming back from the brink to end Jessica Pegula's fine run with a 5-7 7-5 6-0 victory.

The Belgian looked to be heading out when she faced a 5-2 deficit in the second set, yet saved three match points to force a decider.

"I kept on fighting and that was the spirit today," said world number 18 Mertens.

Former world number one Muguruza is Mertens' semi-final opponent, the Spaniard having come from a set down to beat third seed Aryna Sabalenka 3-6 6-3 6-2.

Muguruza lost out to Petra Kvitova in the final of the Qatar Open last week, but looks on top form as she closes in on another championship match.

Sabalenka fell foul of Muguruza in Doha, and the Belarusian was unable to gain revenge as the ninth seed earned a 16th win of the season.

There was to be no place in the last four for 16-year-old Gauff, who came up short against world number 54 Jil Teichmann.

Gauff, who defeated Teichmann twice in Australia in February, was broken to go 5-3 down in the first set and could not respond.

A second break in Teichmann's favour put Gauff on the back foot in the second, and the Swiss then saved three break points to nose into a 3-1 lead.

The contest was settled on Gauff's serve – Teichmann taking the match at the second time of asking to tee up a last-four clash with Barbora Krejcikova, who beat Anastasia Potapova 6-0 6-2 in a little over an hour.

Krejcikova was beaten in the doubles final last year, and has claimed her place in the singles semi-finals of a WTA 1000 event for the first time.

Garbine Muguruza made light work of Iga Swiatek to book her place in the quarter-finals of the Dubai Tennis Championships.

The in-form Spaniard required just one hour and nine minutes to win 6-0 6-4 against the number eight seed and reach the final eight for the fourth time in seven appearances at the tournament.

Reigning French Open champion Swiatek came into the contest on a six-match winning streak but her resistance seemed to falter after she dropped serve in the opening game and then failed to capitalise on two break points in the second.

Muguruza, whose 2021 record now stands at 15 wins and four defeats, was comparatively ruthless against an opponent who landed with just 38 per cent of her first serves.

The former world number one and double grand-slam champion let a 3-1 lead slip in the second set before resuming control through her punishing forehand, getting the job done on the first match point with an ace.

She will be back into action on Thursday against Aryna Sabalenka. The Belarusian, who beat Anett Kontaveit 6-3 6-2, lost in three sets to Muguruza at the Qatar Open last week.

"Back-to-back matches is good," said Muguruza. "That means I'm playing the top players, that means I'm getting into the deep rounds. I'm looking forward for another battle."

Coco Gauff reached the last eight of a WTA 1000 event for the first time after a straight-sets win over qualifier Tereza Martincova.

The American, who turns 17 on the day of the final, won 6-4 6-2 to set up a showdown with Jil Teichmann, a 6-3 6-3 winner over Ons Jabeur.

Second seed Karolina Pliskova was a surprise casualty, losing in less than an hour to Jessica Pegula. The world number 36, who also beat Pliskova in Qatar, will face Elise Mertens after she beat Caroline Garcia 6-4 6-2.

The last remaining former champion in the draw, Belinda Bencic, suffered disappointment on her 24th birthday as she lost 6-1 2-6 7-5 to wildcard Anastasia Potapova. She will take on Barbora Krejcikova, who eliminated Svetlana Kuznetsova.