Belinda Bencic claimed her first win on clay since the 2019 French Open as she saw off teenager Nastasja Schunk at the Stuttgart Open.

The world number 12 eased to a 6-4 6-2 victory over the 17-year-old qualifier, who saved five match points in her final service game before Bencic closed things out.

"My love affair with clay is... I'm trying to improve myself on it," Bencic said after her first-round triumph.

"I think I'm getting better and I'm taking falls sometimes. I'm trying my best on this surface."

Maria Sakkari was similarly comfortable in progressing to the next round, hitting 24 winners as she dispatched Andrea Petkovic 6-2 6-2 on her debut at the tournament.

At the Istanbul Cup, four of the five scheduled matches were completed before rain stopped play with Anastasia Pavlyuchenkova and Anastasia Potapova level at a set apiece.

Eighth seed Wang Qiang fought back from a set down to beat Anastasia Gasanova 4-6 6-1 6-2.

There were also wins for Ana Konjuh, Katerina Siniakova and Viktorija Golubic.

Australian Astra Sharma scored a shock win over top seed Ons Jabeur in the final of the MUSC Health Women's Open, landing her first WTA Tour singles title.

The world number 165 made a slow start to the match but eventually overwhelmed Jabeur 2-6 7-5 6-1 in Charleston.

Having risen to 27th in the world rankings without a trophy to her name, the 26-year-old Jabeur looked to have an ideal opportunity to put that right.

Sharma recovered from the one-sided opening set to lead early in the second, and despite Jabeur getting it back on serve, the underdog surged ahead again to level the contest.

In her second WTA singles final and first for two years, Sharma went one step further than when she was runner-up in Bogota, racing through the deciding set as she swatted away Jabeur's threat.

Jabeur said the defeat was "very tough" to take, while Sharma said of her breakthrough week: "This has been an amazing event. I've really enjoyed playing here."

Ons Jabeur earned revenge on Danka Kovinic with a 6-3 6-0 hammering in the semi-finals of the MUSC Health Women's Open.

It was only a week ago the top seed was defeated by the same opponent on the same Charleston court at the same stage in the Volvo Car Open.

But a day on from needing just 45 minutes to hammer Nao Hibino 6-1 6-0, Jabeur required a little over 90 minutes to progress to Sunday's showpiece.

Jabeur is now 18-7 for the year, with only Garbine Muguruza holding more wins on the WTA Tour in 2021.

On the other side of the draw, Astra Sharma overcame Maria Camila Osorio Serrano 7-6 (7-5) 6-1.

It marks Sharma's second WTA final and her first in two years.

Top seed Ons Jabeur moved through to the MUSC Health Women's Open semi-finals after easing past Nao Hibino.

Jabeur – eyeing her first WTA Tour title – made light work of Hibino 6-0 6-1 in Charleston on Friday.

Next up for the Tunisian is high-flying Danka Kovinic at the WTA 250 tournament.

For the second week in a row, Kovinic reached the semi-finals in Charleston after taking down hometown favourite and third seed Shelby Rogers 7-5 6-1.

Maria Camila Osorio Serrano, who claimed her maiden singles title at the Copa Colsanitas in Bogota last week, was leading 6-4 1-0 when Clara Tauson retired.

Meanwhile, Astra Sharma defeated 15-year-old Czech Linda Fruhvirtova 6-4 6-3.

Ons Jabeur and in-form Maria Camila Osorio Serrano both progressed to the quarter-finals of the MUSC Health Women's Open.

Top seed Jabeur eased past American world number 313 Alycia Parks 6-4 6-0 in Charleston on Thursday.

Eyeing her first WTA Tour title, Tunisian Jabeur will face Nao Hibino for a place in the semi-finals.

Colombia's Osorio Serrano, who claimed her maiden singles title at the Copa Colsanitas in Bogota last week, rallied past Christina McHale 2-6 7-6 (7-2) 7-6 (7-1).

Osorio Serrano and Clara Tauson will go head-to-head in the quarters at the WTA 250 event.

Linda Fruhvirtova – the 15-year-old Czech teen – and Astra Sharma also advanced at the expense of Emma Navarro and eighth seed Madison Brengle.

Shelby Rogers booked her spot in the MUSC Health Women's Open quarter-finals, but fellow seeds Ajla Tomljanovic and Lauren Davis crashed out.

Following her third-round appearance at the Volvo Car Open, Charleston native Rogers moved through to the quarters of her second hometown tournament in as many weeks after easing past qualifier Claire Liu 6-2 6-2.

"I think I was due for a couple of tame matches," said third seed Rogers, who lost to world number one Ash Barty at last week's Volvo Car Open. "I've had quite a few mental battles over the last couple of months, so it's been nice to just take care of business in straight sets, get in and get out."

Next up for Rogers at the WTA 250 event is in-form Montenegrin opponent Danka Kovinic, who upstaged seventh seed Davis 6-1 1-6 6-3 on Wednesday.

Australian sixth seed Tomljanovic was swept aside by teenager Clara Tauson 6-1 6-4, while Nao Hibino beat Francesca Di Lorenzo 6-4 6-3.

Top seed Ons Jabeur advanced to the last 16 at the MUSC Health Women's Open, while Magda Linette was a casualty on Tuesday.

Jabeur – who reached the semi-finals of the Volvo Car Open – made a winning start at the WTA 250 event after toppling Stefanie Vogele 6-4 6-1.

The Tunisian won 88.9 per cent of her first serves to set up a clash with qualifier Alycia Parks – the latter eased past fellow American Grace Min 6-1 6-4.

However, second seed Linette crashed out at the hands of in-form Colombian Maria Camila Osorio Serrano.

Osorio Serrano, who claimed her maiden singles title at the Copa Colsanitas in Bogota last week, upstaged Linette 6-3 4-6 7-5.

Elsewhere, 15-year-old wildcard Linda Fruhvirtova – in just her second WTA main-draw appearance – progressed 6-2 6-7 (7-9) 4-4 after fourth seed Alize Cornet retired in the final set.

Third seed Shelby Rogers eased into the second round of the MUSC Women's Health Open while fifth seed Misaki Doi retired in a three-hour epic on Monday in Charleston.

World number 46 Rogers, who reached the last 16 at last week's Volvo Car Open in Charleston, proved too good for fellow American Caty McNally winning 6-0 6-1 in just over an hour.

Doi's match with countrywoman Nao Hibino lasted much longer, extending to three hours and nine minutes with the latter progressing in a walkover 7-5 5-7 6-6. Doi succumbed to cramps in the third set tiebreaker.

Seventh seed Lauren Davis defeated Coco Vandeweghe 7-6 (7-3) 6-4 in their All American battle while Australian sixth seed Ajla Tomljanovic cruised past Renata Zarazua 6-1 6-1 in the final match of the first day.

Eighth seed Madison Brengle also progressed in three sets past Natalia Vikhlyantseva and unseeded Dane Clara Tauson won 6-3 6-3 over Liudmila Samsonova.

Veronika Kudermetova became the first winner of the Charleston Open since Serena Williams to triumph without dropping a set all week.

The 23-year-old Russian crushed the hopes of Montenegrin rival Danka Kovinic in Sunday's final, landing her maiden WTA Tour title with a 6-4 6-2 victory.

It meant Kudermetova sealed a perfect tournament, winning all six of her matches without being taken to a deciding set, just as superstar and 23-time grand slam champion Williams managed in 2012.

World number 38 Kudermetova said, quoted on the WTA website: "All the matches were really tough. It's really tough matches for nerves, and the tennis part, but I'm really proud of myself that I can take the first title. I'm really happy.

"It means a lot. It shows me that I can play really well, that I can beat good players, and if I play like this and keep working, I think I can be in the top 10 or higher."

The Copa Colsanitas title went to Colombian 19-year-old Maria Camila Osorio Serrano, a former US Open junior champion who entered the tournament on a wildcard but came through the field to also grab a first senior singles title.

She sank the trophy prospects of Slovenian fifth seed Tamara Zidansek, with the world number 180 recording a 5-7 6-3 6-4 victory, describing her success as "unreal".

There will be no dream first WTA Tour final for Paula Badosa at the Charleston Open after she was defeated in the last four by Veronika Kudermetova.

Badosa claimed the biggest win of her career so far in the quarter-finals when she knocked out world number one Ash Barty.

But the 23-year-old, twice beaten in the semis at WTA 250-level events in the past year, came up short against 15th seed Kudermetova.

The Russian was clinical, taking four of her six break point opportunities in a straightforward 6-3 6-3 success.

Kudermetova had previously knocked out Sloane Stephens but will now be favourite against Danka Kovinic.

The underdog's straight-sets defeat of Ons Jabeur in the last four should ensure there is no complacency from Kudermetova.

In Bogota, 19-year-old wildcard Maria Camila Osorio Serrano will play for the title after swatting aside qualifier Harmony Tan 6-1 6-2.

The former top-ranked junior will have to negotiate fifth seed Tamara Zidansek, however, after she defeated Viktoriya Tomova 6-3 7-5.

World number one Ash Barty has been knocked out of the Charleston Open after a straight-sets loss to unseeded Spaniard Paula Badosa in Friday's quarter-finals.

Badosa won 6-4 6-3 over the favoured Australian in one hour, 16 minutes to book a spot in the last four on the green clay and a meeting with 15th seed Veronika Kudermetova.

Kudermetova beat 2017 US Open winner Sloane Stephens 6-3 6-4 in her first win over a grand slam winner.

Former French Open junior champion Badosa, who beat fifth seed Belinda Bencic in the second round, claimed her second career victory over a top-20 player against Barty.

Barty may have hit 34 to 19 winners but she also made twice as many unforced errors, 24 to 12.

The Spaniard broke Barty's serve five times while she sent down seven aces and saved 12 of 14 break points.

"I was quite nervous today but I think I served very well and I think that was the key for the match," Badosa said in her on-court interview.

"It was a tough match but I was there until the last moment and I managed to win."

World number 71 Badosa becomes the lowest-ranked player to beat Barty since September 2019.

The Australian had won eight matches in a row after last week's triumph at the Miami Open.

Unseeded Montenegrin Danka Kovinic came from a set down to topple 11th seed Yulia Putintseva 6-7 (2-7) 7-5 6-1.

Kovinic, who knocked out Petra Kvitova in the third round, will play 12th seed Ons Jabeur in the semi-finals after she overcame Coco Gauff 6-3 6-3.

Meanwhile, at the Copa Colsanitas in Bogota, fifth Tamara Zidansek beat Italy's Sara Errani 6-3 6-4 to claim a spot in the semi-finals.

Viktoriya Tomova outlasted qualifier Nuria Parrizas-Diaz 5-7 6-2 6-4 in almost two and a half hours, while Harmony Tan and local wildcard Maria Camila Osorio Serrano also won.

Top seed Ashleigh Barty moved into the quarter-finals with a three-set win over Shelby Rogers while Petra Kvitova and Garbine Muguruza exited in the Round of 16 of the Volvo Car Open in Charleston.

World number one Barty was pushed all the way by 52nd ranked Rogers, with both players trading breaks in the final set, before the Australian prevailed 7-6 (7-3) 4-6 6-4.

The victory extends Barty's winning streak to eight matches having won last week's Miami Open.

Barty won 82 per cent of first serve points and sent down 10 aces to get the edge on the American, who saved eight of 13 break points throughout the match.

"The conditions are difficult. It's pretty quick," Barty said in her on-court interview post-game.

"Shelby was able to control the centre of court for a lot of the match. It was about trying to get control when I could. She's an exceptional player, it's always a fight no matter what surface or where we are in the world. It's always one that I enjoy."

Barty will play Spaniard 71st ranked Paula Badosa in the quarter-finals after she beat Caty McNally 6-3 6-3.

Third seed Kvitova was the major casualty on Thursday, losing 6-4 6-1 to Montenegrin Danka Kovinic.

The first set was tightly fought before Kovinic pulled away as Kvitova's errors mounted.

"We both have pretty big serves and she's very good hitting from the baseline," Kovinic said post-game. "Today it was the key that I tried, and did it really well, to take her pace of the ball and use her energy."

Sixth seed Garbine Muguruza also bowed out injured, despite leading 6-0 2-2 against 11th seed Yulia Putintseva.

Muguruza laboured for a few games after a medical time-out before retiring with a left leg injury. Putintseva will next face Kovinic.

Seeds Ons Jabeur, Veronika Kudermetova and Cori Gauff also progressed to the last eight, while Sloane Stephens won in straight sets against Ajla Tomljanovic.

Meanwhile at the Copa Colsanitas second round in Bogota, seventh seed Tereza Martincova was knocked out, going down 6-3 6-3 to Colombian teenager Maria Osorio Serrano.

On the outdoor clay courts, fifth Tamara Zidansek moved into the quarter-finals with a 6-2 6-3 win over Giulia Gatto-Monticone, while Harmony Tan beat Daniela Seguel.

The French Open will take place a week later than initially scheduled this year, a move aimed at increasing the possibility of spectators attending the event in Paris.

Action at Roland Garros was due to begin with qualifying on May 17, reverting back to a more traditional time in the tennis calendar after taking place last year in September and October.

That move was made due to the impact of the coronavirus pandemic, taking place after the US Open while Wimbledon was cancelled.

With France currently in a third nationwide lockdown as part of measures to slow the rise in COVID-19 cases, the ATP and WTA Tours released a joint statement on Thursday confirming the main draw at Roland Garros will now begin on May 30 instead.

"Tennis has required an agile approach to the calendar over the past 12 months in order to manage the challenges of the pandemic, and this continues to be the case," the statement read.

"The decision to delay the start of Roland Garros by one week has been made in the context of recently heightened COVID-19 restrictions in France, with the additional time improving the likelihood of enhanced conditions and ability to welcome fans at the event.

"Both the ATP and WTA are working in consultation with all parties impacted by the postponement to optimise the calendar for players, tournaments and fans, in the lead-up to and following Roland Garros.

"Further updates will be communicated in due course."

Rafael Nadal is the defending men's champion, the Spaniard having secured the clay-court title for a 13th time in 2020. However, there was a new winner in the women's tournament, Iga Swiatek of Poland defeating Sofia Kenin in the final.

A statement released from the Grand Slam Board backed the move to postpone the French Open, while also announcing the grass-court season will be reduced by one week as a consequence.

"All four grand slam tournaments are united in their view on the importance of a meaningful build-up to every grand slam, to provide players of all competitive levels with appropriate opportunities to practice, prepare and compete on the relevant surface," a statement released via Wimbledon's official website read.

"It was for this reason that the grand slams, together with the Tours, were supportive of changes to the calendar to create an enhanced grass-court season of three weeks between Roland Garros and the Championships from 2015 onwards. It is widely agreed that this change has been very successfully received.

"However, given the considerable challenges ahead of the FFT in staging Roland Garros, and to avoid further impact on the rest of the calendar, the grass-court season will be reduced by one week in 2021."

Wimbledon will remain as planned, the main draw beginning on June 28 with qualifying taking place the week beforehand.

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.