Anett Kontaveit beat Olympic champion Belinda Bencic and will face home favourite Petra Kvitova for a place in the Ostrava Open final.

Estonian Kontaveit, ranked 30th in the world, claimed her fourth top-20 win of the season as she prevailed 6-4 6-3 on Friday.

Kontaveit also defeated Bencic in the 2020 Australian Open, meaning she is 2-0 in their head-to-head rivalry.

Czech left-hander Kvitova awaits in the last four, after the second seed defeated Bencic's Swiss compatriot Jil Teichmann 6-4 6-4.

Teichmann beat Kvitova in their only previous meeting, but the world number 10 had too much on this occasion, along with the backing of the crowd to boot as she chases a 29th singles title of her career.

The other semi-final will see top seed Iga Swiatek face Maria Sakkari.

Last year's French Open winner Swiatek reached her first semi-final since May – when she landed the prestigious title in Rome – by overcoming Elena Rybakina 7-6 (7-5) 6-2.

Sakkari, meanwhile, ended Tereza Martincova's hopes in straight sets.

Greek star Sakkari ended Swiatek's reign as Roland Garros champion in June, beating the Polish 20-year-old in the quarter-finals in Paris.

US Open champion Emma Raducanu has split from coach Andrew Richardson and wants to partner with someone with greater WTA Tour experience. 

Richardson had coached Raducanu in her younger days at Bromley Tennis Centre and accompanied the 18-year-old for her campaign at Flushing Meadows. 

The experience proved unforgettable as the Briton, ranked 150 in the world at the time and having played in just one other major previously (Wimbledon in July), took the title after moving through qualifying and the main draw without dropping a set. 

She became the youngest grand slam finalist since Maria Sharapova won Wimbledon as a 17-year-old in 2004 and is the only qualifier in tennis history to win a major final. 

Her astonishing triumph catapulted her to 22 in the WTA rankings and Raducanu is now looking for someone to guide her through the next phase of her career. 

Speaking at a homecoming event organised by the Lawn Tennis Association, she said: "Where I was at after Wimbledon, I was ranked around 200 in the world and at the time I thought Andrew would be a great coach to trial, so we went to the States but never did I even dream of winning the US Open and having the run I did, and now I'm ranked 22 in the world, which is pretty crazy to me. 

"I feel like at this stage in my career, and playing the top players in the world, I realised I really need someone right now that has had that WTA Tour experience at the high levels, which means that I'm looking for someone who has been at that level and knows what it takes. 

"And especially right now because I'm so new to it, I really need someone to guide me who has already been through that. 

"Obviously having such an experience with your team, it's tough to have that conversation with anyone, but I think for me, it's just really what I need." 

It has been suggested Raducanu could look to partner with Darren Cahill, the renowned coach who split with Simona Halep this month. 

For now, she is considering when to make a competitive return to action, with the notable Indian Wells Open coming up. 

"I'll decide in the next few days where I'm going to go to but, wherever I play next, I'm going to make sure I'm ready. I don't want to jump into things too early," she said. 

Olympic gold medallist Belinda Bencic eased to a straight-sets win over Sara Sorribes Tormo to maintain her good form and book a place in the Ostrava Open quarter-finals.

Third seed Bencic needed just 88 minutes to see off her 36th-ranked opponent as she made it 15 victories from her past 18 matches.

Czech wildcard Tereza Martincova is also through to the last eight on home soil after battling past French Open finalist Anastasia Pavlyuchenkova 7-6 (7-5) 7-6 (8-6).

Martincova is into her fifth quarter-final of the season and will take on number four seed Maria Sakkari, who saw off Jelena Ostapenko 6-4 6-2 earlier on Thursday.

Also through to round three is Elena Rybakina following a hard-fought 6-3 2-6 6-1 win over qualifier Magda Linette, while Jil Teichmann – who shocked former world number one Angelique Kerber in the previous round – advanced in three sets against Alison Riske.

She will face Petra Kvitova for a place in the semi-finals. 

Former world number one Naomi Osaka unsurprisingly withdrew from next month's Indian Wells Masters, having flagged a break from tennis following her US Open meltdown.

The tournament confirmed 2018 champion Osaka's absence on Wednesday, with the Indian Wells Masters scheduled to take place from October 4-17 after the 2020 edition was cancelled due to the coronavirus pandemic.

Osaka's US Open title defence came crashing down in a remarkable 5-7 7-6 (7-2) 6-4 third-round capitulation at the hands of eventual finalist Leylah Fernandez earlier this month.

Up a set and serving for the match at 6-5 on Arthur Ashe Stadium, four-time major champion Osaka lost her cool and composure after throwing her racquet three times in an unsuccessful second-set tie-break.

Amid boos in New York, Japanese star Osaka was also warned after hitting a ball into the crowd at Flushing Meadows.

After the surprise exit, Osaka told reporters she planned to "take a break from playing for a while."

She added: "I feel like for me recently, like, when I win I don't feel happy. I feel more like a relief. And then when I lose, I feel very sad. I don't think that's normal. I didn't really want to cry.

"I feel like… this is very hard to articulate. I feel like I'm kind of at this point where I'm trying to figure out what I want to do, and I honestly don't know when I'm going to play my next tennis match [tearing up]. Sorry."

It comes following a difficult couple of months due to mental health concerns as a result of "long bouts of depression" since winning the 2018 US Open.

Osaka withdrew from May's French Open having won her first-round match, after she was fined and threatened with further punishment – and possible expulsion from the grand slam – for skipping obligatory media duties.

She subsequently pulled out of Wimbledon before returning for the Olympic Games, though she suffered a surprise loss on home soil in Tokyo and was reduced to tears during a news conference in Cincinnati.

Iga Swiatek coasted through to the quarter-finals of the Ostrava Open after defeating Yulia Putintseva as Paula Badosa faltered against Anett Kontaveit.

Favourite Swiatek provided an astute performance to ease past Putintseva 6-4 6-4 to secure a potential quarter-final tie with Elena Rybakina.

Petra Kvitova, who is second seed in Croatia, did not enjoy as comfortable a victory but battled past Anastasia Potapova 6-1 6-7 (4-7) 6-3 to confirm her last-eight berth.

The ninth ranked Badosa, however, was not as fortunate as she was dumped out by Kontaveit, who cruised to a 6-3 6-4 win over the world number 27 in just over an hour.

Jelena Ostapenko set up a last-16 clash with fourth seed Maria Sakkari as she defeated Anna Blinkova 6-4 6-0, while Alison Riske recovered from a second-set setback to defeat Fiona Ferro 6-4 1-6 6-4.

Riske will now meet Jil Teichmann, who shocked former world number one Angelique Kerber, and whoever wins will be rewarded with a tie against world number 10 Kvitova.

Simona Halep has confirmed she has parted company with her long-time coach Darren Cahill.

Halep, who was the year-end number one in 2017 and 2018, has been coached by Cahill for the past six years.

She won the 2018 French Open, her first grand slam title, under his guidance before Cahill left the team for a spell to spend more time with his family.

Cahill – who also guided Halep to the 2018 Australian Open final – returned to coach the Romanian ahead of the 2019 WTA Finals, following on from her success at Wimbledon.

The 29-year-old has endured an injury-hit 2021 and was knocked out of the US Open in the fourth round by Elina Svitolina.

In a post on her official Twitter account, Halep announced: "After six wonderful years working together, Darren Cahill and I have decided that it's time to end our working relationship.

"Thank you D for everything, for making me a better tennis player and a better person."

Former world number one Angelique Kerber was stunned by Jil Teichmann as she lost 6-2 6-3 in Tuesday's Ostrava Open first-round tie.

World number 42 Teichmann raced to a memorable victory against the three-time grand slam winner in just over an hour as the left-hand collected her sixth win against a top-20 player this season.

Half of those wins have come this year as well, with the Swiss beating Naomi Osaka, Belinda Bencic and Karolina Pliskova in a breakthrough Cincinnati campaign.

Fifth seed Anastasia Pavlyuchenkova cruised through after negotiating a difficult first set against Ana Konjuh to win 7-6 (7-3) 6-1 in just over an hour-and-a-half.

Tereza Martincova's victory over fellow Czech Katerina Siniakova did not come as easily, though, with the former edging to a 5-7 6-4 7-6 (9-7) win in more than a three-hour slog.

Martincova, who is ranked 61st in the world, miraculously recovered from 5-0 down in the tie-break to save a match point before securing her first main-draw win in Croatia.

Yulia Putintseva experienced similar difficulties against Shuai Zhang, as she also battled out in a three-hour marathon and saved a match point to eventually succeed 5-7 7-6 (9-7) 6-4.

Paula Badosa got her campaign off to a winning start as the Ostrava Open began on Monday. 

Iga Swiatek, Petra Kvitova, Belinda Bencic and Maria Sakkari are among the top names at the WTA 500 event, though they are all yet to begin their campaigns. 

World number 27 Badosa was the only seed in action, and she started her week in smooth fashion with a 6-2 6-2 triumph over Russian qualifier Varvara Gracheva. 

In a dominant performance, Badosa did not even concede a break point as she triumphed in 73 minutes to gain some revenge for her defeat to Gracheva at the US Open earlier this month. 

Fellow Spaniard Sara Sorribes Tormo joined Badosa in claiming a first-round victory, though she had to work much harder to see off Anastasia Zakharova. 

While Sorribes Tormo triumphed 6-3 6-3, she was given a stern examination by Zakharova, who forced nine break points in the contest but paid the price for converting just two. 

The prize for Sorribes Tormos is a testing last-16 tie against Olympic gold medallist Bencic. 

Caroline Garcia, meanwhile, was a day one casualty as she lost in straight sets to Anastasia Potapova. 

Potapova will now take on two-time Wimbledon champion Kvitova, who will be playing in front of her home fans in the Czech Republic. 

Jasmine Paolini battled to a straight-sets victory over Alison Riske in Sunday's Portoroz final to win her maiden WTA singles title.

World number 87 Paolini had already eliminated three seeded players to reach her first final and she recovered from a slow start to see off another 7-6 (7-4) 6-2.

Third seed Riske led 5-2 in the first set after breaking her opponent's serve three times in the opening seven games, but Paolini dug deep and took four games on the spin.

The Italian used that momentum in the tie-break to open up a 5-2 advantage before getting over the line with her second set point.

After a gruelling 63-minute opening set, Paolini found the second a more straightforward affair as she broke for 3-2 and reeled off the remaining games, the last of those points coming via an error-forcing forehand.

Paolini, who won two-thirds of her second-service points and converted six of her 10 break points, is glad her hard work has paid off with a first singles success at the age of 25.

"It's been an amazing week here in Portoroz," she said in her on-court interview. "I feel just very happy, it's a big achievement for me, to win my first title. It's special to do it on the hard court.

"It wasn't easy to go through to the final. I'm proud of myself because I never gave up.

"I'm working really hard in the past couple of months. I understood more about my game, I think. I just want to keep this level for all the season that is almost finished, and to stay strong and keep this level."

Danish teenager Clara Tauson set up a Luxembourg Open final showdown with Jelena Ostapenko, showing off the prowess that saw her beat Emma Raducanu in Chicago prior to the US Open.

Raducanu recovered from that setback in the final of August's Challenger tournament in the Windy City, charging to a shock Flushing Meadows triumph, but fellow 18-year-old Tauson awaits her big breakthrough at the majors.

Tauson took down a former French Open runner-up and current Olympic silver medallist in reaching the Luxembourg final, beating Marketa Vondrousova in three sets, and now must overcome a player who has been champion at Roland Garros in Ostapenko.

She prised the vital break of serve in the ninth game of the decider against Vondrousova, upping the power in her shots, before serving out for a 6-4 2-6 6-4 victory.

Tauson will be going for a second title of the year, having won the Lyon Open in March.

Defending champion Ostapenko raced to a 6-1 5-1 lead over Liudmila Samsonova but then began to misfire and had to scramble from the brink of being taken to a third set.

Ostapenko eventually prevailed 6-1 7-6 (7-4), having trailed 4-1 in the tie-break, and she will attempt to scoop a fifth WTA title on Sunday. Her most recent came at Eastbourne in the week before Wimbledon.

At the WTA tournament in the Slovenian town of Portoroz, Sunday's final will feature American Alison Riske and Italy's Jasmine Paolini.

Riske denied Slovenian Kaja Juvan a place in a home final, earning a 6-0 6-4 win in their semi-final, while Paolini sprang a shock by beating Kazakhstan's Yulia Putintseva 1-6 6-3 6-4.

Belinda Bencic made a winning return to action as the Olympic champion defeated Zarina Diyas to seal a quarter-final spot at the Luxembourg Open.

Bencic, the unlikely successor in Tokyo, triumphed in straight sets 6-1 6-3 on Thursday to tee up a last-eight encounter with Liudmila Samsonova, who the Swiss lost to in Berlin earlier this year.

It was a welcome return to form for world number 12 Bencic after her defeat to eventual champion Emma Raducanu in the US Open quarter-finals last week.

Joining the top seed in the quarters is defending Luxembourg Open champion Jelena Ostapenko, who needed three sets to overcome Arianne Hartono.

Second seed Elise Mertens also progressed, though she had to come from behind to beat Aliaksandra Sasnovich 3-6 6-2 7-5.

In Thursday's other last-16 tie, Marie Bouzkova beat Greet Minnen to round off the quarter-finals line up.

Meanwhile, Sorana Cirstea and Jasmine Paolini will meet in the Zavarovalnica Sava Portoroz quarter-finals after respective victories over Tereza Martincova and Anna Kalinskaya.

There was a sense of deja vu as Clara Tauson upset fourth seed Ekaterina Alexandrova at the Luxembourg Open.

The 18-year-old defeated the same opponent en route to claiming a maiden WTA Tour title in Lyon in March and repeated the feat here, again on an indoor court.

On this occasion, Tauson needed to come back from a break down in the deciding set to clinch a 6-4 3-6 7-6 (7-1) triumph and book her spot in the quarter-finals.

Fifth seed Marketa Vondrousova had no such trouble, the Czech a comfortable 6-2 6-4 victor over Jana Fett. Alize Cornet (8) also made the last eight with a 6-3 6-3 win over Mandy Minella, while Ludmilla Samsonova (7) needed a pair of tie-breaks to overcome Oceane Dodin.

In the first round, Zhang Shuai (6) lost in three sets to Marie Bouzkova.

At the Zavarovalnica Sava Portoroz in Slovenia, second seed Yulia Putintseva was a 6-3 6-1 winner over Katie Boulter. Alison Riske, Kristina Mladenovic and Lucia Bronzetti also made it through.

Emma Raducanu still has the hunger to continue improving following her record-breaking US Open triumph and is targeting a possible return to action at Indian Wells.

The 18-year-old became the first qualifier in history to win a grand slam when defeating Leylah Fernandez ​in straight sets in Saturday's final at Flushing Meadows.

Raducanu, ranked 150 by the WTA before beginning her three-week long tournament, did not drop a single set across her 10 matches.

That victory in New York capped a life-changing couple of months for Raducanu, who also reached the last 16 of Wimbledon in her only other grand slam appearance before withdrawing due to medical reasons.

After spending a few days away from the court and taking in some of the sights the Big Apple has to offer, the Briton is ready to start preparing for her next tournament.

"I have a few days' rest and recovery," Raducanu, who became the first British female to win a major tournament since Virginia Wade on home soil at Wimbledon 44 years ago, told CNBC's Closing Bell programme.

"I think it was needed after the last seven weeks but then I am straight back to training and hungry to get better and come back out and play some more tournaments."

Raducanu was originally due to take part in qualifying for the Chicago Fall Tennis Classic later this month, but she may instead wait for next month's delayed Paribas Open in Indian Wells, where a wildcard entry is likely.

"After the US Open I wanted to give myself this week to completely switch off from tennis because it's been an extremely intense but rewarding seven weeks," she told the WTA's official website. 

"But I've worked very hard to finish on such a high with the US Open, a whole week off was needed.

"I know I'll get back to work probably Monday or early next week to get back to training again. Schedule-wise, I'm not sure. Maybe Indian Wells, I don't know. I'm going back to London before my next tournament for sure."

Defending champion Jelena Ostapenko booked her place in the last 16 of the Luxembourg Open with a comfortable straight-sets win over Jule Niemeier.

The world number 30 came out on top 6-2 6-2 in a little under an hour to set up a meeting with Arianne Hartono, who earlier beat Anna-Lena Friedsam 7-6 (7-5) 3-6 7-6 (7-4).

Fifth seed Marketa Vondrousova also shuffled through to the next round thanks to a 6-2 6-3 triumph against Alison Van Uytvanck, while Zarina Diyas will face tournament favourite and Olympic champion Belinda Bencic next after beating Anna Karolina Schmiedlova in three sets.

Aliaksandra Sasnovich was made to work harder for her 7-5 7-6 (8-6) win against Lesia Tsurenko, with that the longest straight-sets match of 2021 so far at two hours and 30 minutes, according to the WTA.

Greet Minnen and Mandy Minella were also victorious on Tuesday, overcoming Nuria Parrizas-Diaz and Varvara Gracheva respectively.

At Zavarovalnica Sava Portoroz in Slovenia, meanwhile, home favourite Kaja Juvan eliminated top seed Petra Martic with a 6-3 6-4 win. Sweden's Rebecca Peterson was another seed to fall, going down in straight sets to Lucia Bronzetti.

Dominic Thiem believes Emma Raducanu's sensational US Open triumph might be the "greatest breakthrough performance of all time".

Raducanu, 18, overcame fellow teenager Leylah Fernandez 6-4 6-3 on Saturday to cement her place in history.

Her triumph meant she became the first qualifier – male or female – in tennis history to win a grand slam final.

She did not lose a set in 10 matches across qualifying and the main draw, becoming the first player since Serena Williams in 2014 to win the US Open without dropping a single set.

Raducanu – whose first grand slam appearance only came at Wimbledon in June – was ranked 150th in the world before the US Open, but her stunning win in New York has seen her break into the top 30.

Thiem, who missed the men's tournament with a wrist injury, was in awe of Raducanu's stunning run at Flushing Meadows and says he can scarcely recall a more impressive breakthrough in the sport.  

"There were some other great achievements in the past but with Emma Raducanu, starting in the qualifiers and then playing such great tennis and making this incredible path, it's definitely, maybe, the greatest breakthrough performance of all time," he exclusively told Stats Perform.

"It's an incredible journey if you look at the stats. She didn't lose one set the whole tournament. She came from qualifying and she didn't even play one tie-break. That's simply amazing and something that was probably never witnessed before.

"And also the way she plays, her technique, the way she moves, somehow she brought it up to a new level for the whole game and it was great to see.

"But as well, her opponent, it was so fun to watch her. I was excited for it, watching every single point on TV. And it was great not only for women's tennis, but for all sports in general."