Petra Kvitova came from a set down to beat Katarzyna Piter on her return from injury at the Bad Homburg Open, while no play was possible in Eastbourne on Monday due to rain.

Kvitova withdrew from the French Open after suffering a freak ankle injury during her post-match media duties at Roland Garros.

The two-time Wimbledon champion recovered to get her grass-court season under way in Germany and battled to a 4-6 6-1 6-4 over Polish outsider Piter.

A week before the third grand slam of the year gets started at the All England Club, top seed Kvitova trailed 2-0 in the final set as she struggled with her serve, but broke three times to book a second-round meeting with Ann Li.

Sloane Stephens withdrew ahead of her scheduled match with Laura Siegemund due to a foot injury. Riya Bhatia stepped in with Stephens absent, but Siegemund consigned her to a 2-6 7-6 (7-1) 6-1 defeat.

Angelique Kerber needed only 50 minutes to see the back of Ekaterina Yashina 6-1 6-1 on home soil, grasping all five break-point opportunities.

Kerber will do battle with Anna Blinkova in round two and Jessie Pegula's next assignment is an encounter with Katerina Siniakova following a 6-1 6-2 defeat of Amandine Hesse.

Blinkova beat Clara Tauson 7-6 (7-4) 4-6 6-2, while Sara Sorribes Tormo saw off Martina Trevisan 6-4 3-6 6-2

Miserable weather in Eastbourne prevented Karolina Pliskova, Madison Keys, Bianca Andreescu and Madison Keys from playing at the Viking International.

Britain's biggest hope for Wimbledon glory believes All England Club absentee Naomi Osaka deserves admiration for her impact on and off the court this year.

Johanna Konta beat Osaka three times before the Japanese player went on a stratospheric rise, and she still holds that 3-0 record, given the pair have surprisingly gone four years without facing each other on tour.

While Konta will bid to become a first British champion in the Wimbledon women's singles since 1977 winner Virginia Wade, superstar Osaka has elected to skip the grand slam which begins next Monday, just weeks after withdrawing from the French Open.

Osaka is the reigning US Open and Australian Open champion, but she abandoned her Roland Garros campaign on May 31 after a first-round win and revealed a long-endured battle with depression.

She made that announcement a day after the grand slams warned she could be thrown out of their tournaments for repeatedly skipping mandatory post-match media duties, with Osaka receiving messages of support from the likes of Serena and Venus Williams and Billie Jean King.

The 23-year-old had already declared she would not take part in media conferences during her stay in Paris for the sake of her mental health, questioning the set-up of such interviews and why sporting bodies insist stars must always take part. She faced criticism from some quarters but has started a wider, valuable conversation about how athletes are treated.

Osaka, who last year was ranked by Forbes as the highest-paid female athlete in world sport, has been a powerful and uncompromising voice on race and gender inequality issues, with Konta impressed by the impact such a young player is having.

"As a tennis player she's a four-time grand slam champion already, so she's an incredibly gifted, good tennis player and she is reaching the results that prove that as well," said Konta, a Jaguar ambassador.

"I think for the game, she'll probably be around and be successful for quite some time to come.

"She has a big passion for social movements and current social matters and she feels empowered by using her voice in ways she feels is beneficial to things that she believes in and that's her prerogative to do so.

"And I think that as long as people stay authentic to themselves and what they believe in, I think they make the biggest positive impact they can, and that is the rule of thumb that she's following.

"Obviously a lot of people will find a lot of solace in someone as successful as her talking about things that maybe they experience but don't have the sort of social platform or, I guess, strength of voice to be able to put it in the public domain. Kudos to her for being true to herself."

Konta's wins over Osaka came at the second-round stage of the 2015 US Open, the same round at the 2017 Australia Open, and later in 2017 in Stuttgart.

Their next meeting could come at the Tokyo Olympics, with both planning to take part, Osaka hoping to strike what would be a famous gold for Japan.

The best tennis of Konta's 2021 season so far saw her land a grass-court title at the Nottingham Open this month, becoming the first British woman to win a WTA singles tournament on home soil since Sue Barker did so at the Daihatsu Challenge event in Brighton in 1981.

It gave Konta a first trophy since winning the Miami Open in 2017 and a fourth career title, with the former world number four hitting her stride in timely fashion ahead of a Wimbledon tilt.

For any British player at Wimbledon, attention can be intense, but that is particularly the case for the few who have enjoyed success on a scale Konta has experienced, reaching the semi-finals in 2017 and getting through to the quarters two years ago, the last time the tournament was held.

She has found ways to alleviate the pressure from her own perspective, explaining how she took the heat out of situations so successfully in previous championships.

"Playing in 2017 and getting to the semis there, I didn't feel too overwhelmed by attention," Konta, 30, said in an interview with Stats Perform.

"I think attention can only be too overwhelming if you put yourself in the position where you are looking for it and acknowledging it.

"For me, I would wake up, have breakfast, get in my own car and drive myself to the site, warm up and play my match and do the media and all that, then I'd get in my car and come home, have dinner, watch a series or watch a film, but I wasn't spending my time on social media, I wasn't watching the news, I wasn't really doing too much.

"The only time I noticed that things were happening was when I needed to pop to the supermarket to get some food, and all the newspapers that were there had my face on them, so that was an interesting one."

:: Johanna Konta is a Jaguar ambassador. Jaguar is the Official Car of The Championships, Wimbledon. To discover Jaguar’s unmatched experiences visit jaguar.co.uk/Wimbledon

Qualifier Liudmila Samsonova battled back from a set down to beat Belinda Bencic in Sunday's bett1open final for her first WTA title.

Samsonova became the first qualifier to reach a WTA 500 final this season by shaking off Victoria Azarenka in the semis and followed that up with victory over fifth seed Bencic.

The world number 106, competing in her first career final, held serve in the final two sets to win 1-6 6-1 6-3 in a time of one hour and 37 minutes in Berlin.

Bencic was seeking a fifth WTA title and stormed into a 5-0 lead in a one-sided opening set, but Samsonova soon found her rhythm and hit back in the second.

The Russian broke her opponent's service game in the second and fourth games to level up the contest and earned an early break in the deciding set.

Samsonova did not look back and got over the line on her second championship point by forcing Bencic into a netted backhand with a strong return.

She ended the match with 28 winners to just 15 unforced errors and will move into the world's top 100 following victories over Madison Keys, Azarenka and Bencic in this breakthrough week.

Ons Jabeur got her first WTA singles title on the board as she overcame Daria Kasatkina to win the Viking Classic in Birmingham.

In her third career final, the Tunisian second seed prevailed 7-5 6-4.

Jabeur's victory saw her inflict defeat on fourth seed Kasatkina, who won a Moscow title-match showdown between the pair in 2018. The other final defeat for Jabeur came earlier this year in Charleston.

The triumph adds to what has been a superb season so far for Jabeur. She has 28 match victories in 2021, matching world number one Ashleigh Barty's tally – no player has more.

Jabeur faced a tough opponent in the form of Kasatkina, who had won the previous two meetings between the pair and has claimed two titles this season.

World number 24 Jabeur started with real intent, breaking immediately, yet Kasatkina hit straight back and then saved three set points.

Jabeur took the set at the fourth time of asking, however, and two breaks got her clear in the second set, with the win wrapped up at the first opportunity when Kasatkina found the net.

Qualifier Liudmila Samsonova continued what she described as an "unbelievable" run by upsetting Victoria Azarenka to seal a place in the bett1open final in Berlin.  

The world number 106 reached her first career final by beating two-time major champion Azarenka 6-4 6-2, having impressively seen off Madison Keys in the last eight.

It took just 66 minutes for Samsonova to win as she put on a powerful display of hitting on Saturday, firing down 11 aces.

The 22-year-old did not lose serve in the match and is the first qualifier to reach a WTA 500 final this season.

"It's all incredible for me, it's so new, and I'm very happy for it," Samsonova said amid a week that will give her a rankings surge.

"It’s unbelievable for me. It is the most important [week] of my life up to this moment. 

"I'm sure it’s going to be a tough match because [Bencic] plays very good on this surface, and she's a good player. I will try to do my best and focus on my game, and we will see."

Fifth seed Bencic battled to a 7-5 6-4 victory over Alize Cornet in her last-four clash and will go into the final as favourite.

While the win came in straight sets, it was a hard-fought encounter, with Bencic winning all four of her break points while Cornet forced 10 but only converted two, which proved to be the difference.

Bencic, who will be encouraged ahead of Wimbledon, has now made four grass-court finals in her career and will seek her first WTA Tour title since October 2019 on Sunday.

The Swiss star, who had 29 winners and just 19 unforced errors against Cornet, lost to Iga Swiatek in Adelaide earlier this year in her only final appearance since that last title.

"I always try to play as many tournaments on grass as possible because I just love the surface," Bencic said.

"Of course it gives me a lot of confidence. It's always great to have this confirmation on grass that it is working well."

Simona Halep will not make her comeback in the inaugural Bad Homburg Open but remains hopeful of being fit to defend her Wimbledon title.

The two-time grand slam champion has been sidelined since suffering a calf injury during her a second-round match against Angelique Kerber at the Internazionali d'Italia in Rome last month.

Halep was due to feature in a new grass-court tournament in Bad Homburg, which starts on Sunday, but is not ready to return.

The world number three is determined to be back at full fitness to feature in the third major of the year at the All England Club.

She revealed in a social media post on Saturday: "I will not compete because my calf is not ready for a competition. I feel sorry about that and sad, because it's a beautiful place.

"I will keep practising because I really want to be able to play at Wimbledon, but for now I have to take care of my body and see how the recovery is going.

Wimbledon gets under way on June 28, having been cancelled last year due to the coronavirus pandemic.

Belinda Bencic let anger fuel her progress to the semi-finals of the bett1open in Berlin on Friday.

Bencic – the fifth seed – needed a third-set tie-break to see off Ekaterina Alexandrova 6-4 4-6 7-6 (7-4).

The Swiss will face Alize Cornet at Steffi Graff Stadion in Saturday's semi-final, after the latter upset two-time grand slam winner and world number 13 Garbine Muguruza – similarly going the distance to prevail 4-6 6-3 7-6 (7-5) and saving match point at 5-4 in the tie-break.

Bencic had lost two of her previous three encounters with Alexandrova and conceded to having problems with her opponent's playing style after a fired-up performance at the WTA 500 event.

"I have to get mad," she said. "When I'm mad, I play better, I'm just hitting the ball. So I'm trying to get mad on court."

"I definitely don't like playing her," said Bencic afterwards. "There's not so much rhythm, she's very aggressive player, it's tough to stay in the rally. I would say I'm more relieved [to reach the semi-finals].

The other semi-final pits two-time slam champion Victoria Azarenka against qualifier Liudmila Samsonova.

Former world number one Azarenka battled to see off Karolina Pliskova's conqueror Jessica Pegula 6-2 5-7 6-4, gaining a measure of revenge over a player who dumped her out in the first round of the Australian Open this year.

Samsonova stunned Madison Keys, with a deciding tie-break again required, albeit one that was emphatically dealt with as the world number 106 won 7-6 (7-4) 2-6 7-6 (7-0).

Naomi Osaka will not take part in Wimbledon, but is expecting to return to the court in time to feature for Japan at the Tokyo Olympics.

Osaka withdrew from the 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.

The four-time grand slam champion had confirmed before Roland Garros that she would not be taking part in post-match news conferences, suggesting her mental health was not helped by having to attend the mandatory interviews.

Osaka, the world number two, stated she has had "long bouts of depression" since winning the 2018 US Open title.

With Wimbledon starting at the end of June, Osaka has decided to skip the third grand slam of the year, and instead take time away from tennis.

However, she aims to be back to represent Japan in their home Olympic Games, which start next month.

A statement from Osaka's representatives confirmed that she will miss Wimbledon while taking some personal time with friends and family, but that she will be ready for the Olympics.

The 23-year-old's withdrawal came on the same day that Rafael Nadal – a beaten semi-finalist at Roland Garros – confirmed he would not play at Wimbledon or the Olympics.

Nadal, 35, explained that the quick turnaround from a gruelling campaign in Paris to another tough schedule at Wimbledon presented too much of a risk to his fitness.

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.

The US Open is set to be the first tennis grand slam to operate at full spectator capacity for its duration since COVID-19 became a global crisis.

Tournament organisers said on Thursday that the major, which was played behind closed doors in 2020, would not impose reduce attendance measures this year.

"New York is back, and so are the fans," a statement on the tournament's website said. "The 2021 US Open will welcome fans back to the USTA Billie Jean King National Tennis Center at 100 per cent capacity for the two-week tournament."

Mike Dowse, chief executive of the United States Tennis Association (USTA), said: "We are extremely excited to be able to welcome our incredible fans back to the US Open this year.

"While we were proud that we were able to hold the event in 2020, we missed having our fans on-site, because we know that they are a large part of what makes the US Open experience unlike any other.

"Indeed, the challenges presented by the pandemic were tough on us all, but our sport came together like never before and tackled each challenge head on."

Dowse added: "Our sport surged in the toughest of times, and this year's US Open promises to be an unforgettable celebration of the game, those who play it, and those who revel in it."

The tournament added that it would follow all COVID-related guidelines, although its intention clearly is to run the major in as normal a manner as is possible.

The US Open's announcement came on the day tickets went on sale for the upcoming Wimbledon championship, which begins on June 28. The grass-court slam was cancelled last year.

Wimbledon will operate at a 50 per cent attendance restriction for much of its duration, although the weekend of the finals is due to see Centre Court at 100 per cent capacity.

The French Open functioned with a vastly reduced number of tickets available in both its 2020 and 2021 editions, compared to previous years.

The Australian Open in February capped spectator numbers at 30,000, although a snap lockdown in Melbourne meant there were no crowds for five days midway through the event, with Rod Laver Arena then limited to approximately 50 per cent capacity for the closing stretch of the event.

Naomi Osaka and Dominic Thiem won the women's and men's singles titles at the 2020 US Open, and this year's tournament runs from August 30 to September 12.

Kiki Bertens will retire at the end of the WTA Tour season at the age of 29.

Bertens revealed in a media conference on Wednesday that a combination of the COVID-19 pandemic and an ongoing Achilles injury prompted her to start a new chapter in her life.

A winner of 10 WTA Tour singles and 20 doubles titles, Bertens reached a career-high fourth in the rankings two years ago.

Bertens, now ranked 20th in the world, embarked on her best grand slam run at the 2016 French Open, reaching the semi-finals at Roland Garros.

She was knocked out in the first round of the Paris major Polona Hercog by this time around and made the decision to quit this year after bowing out in the French capital.

Former world number ones Andy Murray and Venus Williams have been given Wimbledon wildcards.

Three-time grand slam champion Murray missed the French Open to focus on the grass-court season, having been troubled by a groin injury.

The 34-year-old Brit, ranked 124th in the world, was emotional after beating Benoit Paire 6-2 6-2 in his first ATP Tour singles match since March on Tuesday.

Murray's career was in doubt after he underwent hip resurfacing in 2019, but the 34-year-old double Wimbledon champion will play in his home major at the All England Club.

Williams, a winner of five Wimbledon singles titles and a six-time doubles champion at the grass-court major, also received a wild card after dropping out of the top 100 in the rankings.

The 40-year-old American will be in the singles draw 21 years after winning her first Wimbledon title.

Wimbledon did not take place last year due to the coronavirus pandemic, but will be the first major outdoor sports in England to be staged with full capacity crowds for the finals weekend of July 10-11.

The Championships will start at SW19 on June 28 with 50 per cent capacity across the venue grounds, Centre Court and No.1 Court. Smaller show courts will be allowed to open at 75 per cent capacity from day one.

From the fourth round, the aim is to increase allocations for Centre Court and No.1 Court, rising to 100 per cent for the finals.

Garbine Muguruza, Victoria Azarenka and Angelique Kerber all sailed through at the bett1 Open on Tuesday as eighth seed Karolina Muchova crashed out in the first round.

The three former world number ones each made relatively light work of their opening clashes in Berlin, with Muguruza seeing off Sorana Cirstea 6-3 6-2.

Muguruza, the 2017 Wimbledon champion, expressed satisfaction with her performance on a return to the grass courts, with that part of the season wiped out in 2020 by the coronavirus pandemic.

"Very pleased," Muguruza said on court after going 24-8 on the season.

"You never know how it's going to go in the first match, especially on grass after two years, so I'm very excited to win in two sets against Sorana.

"We've played many times, and it's always difficult."

She will next face Elena Rybakina who, after beating Serena Williams en route to the French Open quarter-finals, came from a set down to see off Shelby Rogers.

Azarenka was a 6-4 7-6 (7-2) winner over Andrea Petkovic, and the two-time Australian Open champion will now face Kerber for a place in the last eight.

Kerber routed Misaki Doi 6-2 6-1 in a match that lasted only an hour but has lost nine of her previous 10 meetings with Azarenka.

The 2018 Wimbledon champion said: "I will try to play my game, and try to take another chance, and play as many matches as I can before I go to Wimbledon.

"It's another good match at a high level, and this is why I'm here. The draw is really strong, so it's good to have another good match."

Muchova, though, fell at the first hurdle. The Czech suffered an upset in the third round of the French Open at the hands of Sloane Stephens and lost in three sets in the German capital to Veronika Kudermetova after two hours and 27 minutes.

Elsewhere in the draw, there were wins for Petra Martic, Liudmila Samsonova and Jessica Pegula, whose opponent Hailey Baptiste retired in the first set.

There will be capacity crowds for the Wimbledon finals next month and around 45,000 people are set to be allowed into Wembley for the Euro 2020 semi-finals and final.

Prime Minister Boris Johnson on Monday announced a four-week delay in lifting coronavirus lockdown restrictions in England to July 19 due to rising cases of the Delta variant.

However, Wimbledon and the European Championship are being treated as test events, so there is set to be a full house of 15,000 on Centre Court for the championship matches on the weekend of July 10-11.

The grass-court grand slam will be the first outdoor sporting event to have a capacity crowd since the start of the pandemic.

When the tournament, which was not staged last year due to the COVID-19 crisis, starts on June 28 it will be at 50 per cent capacity.

A statement from the All England Club said: "We are pleased to have worked closely with the government, public health bodies, and our local authority in Merton, to confirm that, as part of this next phase of pilot events, The Championships 2021 will begin on Monday 28 June with 50 per cent capacity across the Grounds, building to full capacity crowds of 15,000 on Centre Court for the finals weekend.

"This will enable us to fulfil our aspiration of staging the best Wimbledon possible within the current circumstances, with the health and safety of all those who make Wimbledon happen - our guests, competitors, members, staff, media, officials, local residents, and partners - remaining our highest priority."

Crowds for England's first two Euro 2020 group games at Wembley have been capped at 22,500, but that figure is expected to be doubled so the stadium is half full for the semi-finals and final.

The semi-finals will be staged on July 6 and 7, with the final held on July 11.

Culture Secretary Oliver Dowden said: "We want to gather further evidence on how we can open up all big events safely, and for good.

"The expansion of trials of the NHS app and lateral flow testing will mean that bigger crowds will be able to attend a limited number of major sporting and cultural events early this summer as part of our events research programme.

"In the next few weeks, this means more fans enjoying the Euros and Wimbledon, and some of our biggest cultural and sports events."

Belinda Bencic got her grass-court season under way with a battling victory over qualifier Jule Niemeier in the first round of the inaugural bett1 Open.

Fifth seed Bencic came from a set down to beat 167th-ranked German Niemeier 4-6 6-4 7-5 in Berlin on Monday.

The 21-year-old Niemeier was playing her first professional match on grass and gave a great account of herself against the world number 12, who needed two hours and 12 minutes to secure her place in the second round.

Bencic secured the only breaks in the second and third set to ensure she will face Petra Martic or Asia Muhammad in round two.

Madison Keys progressed in straight sets, getting the better of Polish qualifier Magdalena Frech 6-3 6-4.

The American, a winner of two WTA singles titles on grass, struck 19 winners as she set up an encounter with top seed Aryna Sabalenka.

There were also first-round victories for Alize Cornet and Ekaterina Alexandrova earlier in the day over Amanda Anisimova and Anna Kalinskaya respectively.