Naomi Osaka was forced to retire from her China Open meeting with Coco Gauff due to a lower back injury, sending the American through to the quarter-finals.

Osaka, who was aiming for her fourth successive win after returning from maternity leave, had earlier caused Gauff plenty of problems as she took the opening set.

After a series of breaks to open the match, Osaka went into the changeover 3-2 up but received treatment on her back after appearing to struggle with her movement.

Some error-prone play by Gauff allowed Osaka to clinch a third break before serving out the opener, but she swiftly gave up a break to go behind in the second set.

Gauff ultimately edged a hard-fought, 51-minute second set featuring several more breaks, with Osaka retiring before the decider could get underway, having struggled to land her first serves in the latter stages.

Gauff now advances to the China Open quarter-finals for the second year in a row, with Ukraine's Yulia Starodubtsewa up next for the world number six.

Fellow American and second seed Jessica Pegula, meanwhile, was beaten in straight sets by Paula Badosa, who will face home favourite Zhang Shuai in the last eight.

Data Debrief: Twenty up for Gauff

The victory may not have come in the manner she envisaged, but Gauff has brought up her 20th career win over a former grand slam champion on the WTA Tour.

Since 2000, Gauff is the fifth player to achieve 20 such wins before turning 21, along with Maria Sharapova, Kim Clijsters (28 each), Martina Hingis (24) and Serena Williams (22).

Naomi Osaka is confident she will be able to gain control of her tie with Coco Gauff at the China Open.

Osaka defeated Katie Volynets 6-3 6-2 on Monday to progress to the last 16 in Beijing.

And the four-time grand slam champion's reward was a meeting with world number six Gauff.

The duo have played each other on four occasions, splitting the head-to-head record with two wins each, though their last meeting came in 2022, with Gauff winning in straight sets.

"She's very athletic obviously. For me, my strongest traits are being aggressive and also my serve," Osaka said.

"So it's definitely going to be a battle - who wants to take control of the point first? And I think it's going to be me."

Osaka's tie with Gauff will represent the first time two former grand slam winners will meet in the last 16 at the China Open since 2016, when Petra Kvitova overcame Garbine Muguruza.

World number two Aryna Sabalenka also sealed her progress on Monday, beating American Ashlyn Krueger 6-2 6-2.

"Control over my emotions, that's the key," said US Open champion Sabalenka, who will face Kruger's compatriot Madison Keys in the next round.

"Before it felt like if I'm not going to win this match, something bad is going to happen. I'm going to die," she explained.

"Nowadays I'm just working hard, I'm trying to improve myself every day. Every time I'm on the court, I'm trying to give my best. If you give your best but you didn't win the match, it's okay."

Sabalenka has now registered 800 winners in WTA 1000 tournaments during 2024, while she is the only woman during the Open Era to register a win percentage of over 80% in WTA tournaments held in China (81.3%, 39-9, minimum10 matches played).

Naomi Osaka rallied to beat Yulia Putintseva in the second round of the China Open on Friday, ending a wait of over two years for a comeback victory.

Osaka came from a set down to win 3-6 6-4 6-2 and tee up a third-round meeting with Katie Volynets, extending her winning streak at the Beijing event to eight matches.

She had failed to win any of her previous 22 matches when going a set down, a streak she was mightily relieved to snap.

"I heard that stat from my agent," Osaka told reporters after her win. 

"I wanted to break it really badly because I knew that I also had a stat about three-setters before I took my break, so that was really important to me.

"I also wanted to show myself that I could win a match and fight without playing as perfectly as I wanted to."

Data Debrief: Back-to-back for Osaka

This is the first time Osaka has won back-to-back matches since June at 's-Hertogenbosch, where she reached the quarter-finals before falling to Bianca Andreescu.

The last time she won from a set down, meanwhile, was in the Miami Open semi-finals in 2022, when she beat Belinda Bencic before losing to Iga Swiatek in the final.

Naomi Osaka beat Lucia Bronzetti 6-3 6-2 in the first round of the China Open on Wednesday, in her first match under Serena Williams' former coach Patrick Mouratoglou.

Osaka was returning to the Beijing event for the first time since triumphing there in 2019, and she rallied after going a break down in the first set, ultimately winning comfortably.

The four-time major champion smashed 30 winners to Bronzetti's seven in the one-hour, 23-minute contest, teeing up a second-round clash with Yulia Putintseva.

Speaking after her win, she admitted she had harboured doubts over Mouratoglou initially but was now convinced she has found the right coach.

"I think the fact he was Serena's coach made me want to avoid him," she said. This isn't rude because I found out it's not true, but I didn't know if he was a good coach or he just coached Serena!

"Then I met him, talked to him, worked with him on the court. He absolutely is a really good coach. I'm really glad that he's taking this project on, as well." 

Data Debrief: Osaka's hard-court success

Osaka's victory means she now holds a 72.3% win percentage on hard courts at WTA 1000 events and grand slams (102 wins, 39 defeats).

Only three active players have a better such win ratio; Iga Swiatek (78.3%), Victoria Azarenka (75.5%) and Aryna Sabalenka (73.8%).

Naomi Osaka's wait for a deep run into a grand slam rolls on after the former world number one was beaten by Karolina Muchova at the US Open.

Osaka, a two-time champion at Flushing Meadows, lost 6-3 7-6 (7-5) on Thursday.

She came up against a player in fine form in Muchova, with the Czech displaying the quality that saw her reach the semi-finals a year ago.

"I was just really trying to be focused," Muchova said.

"I know she's an amazing player and that I have to bring the A-game to have a chance. So I was just trying to be really focused on myself. I knew I had to serve well because her serve is really good. So I was just trying to be kind of locked in myself and focused out there."

"Then the energy and the big court and all that, it for sure helps me. I like that."

Osaka, meanwhile, suggested the nerves got to her on Arthur Ashe Stadium.

"I think during the pressure moments I got nervous," Osaka said, and I don't know if I just have to keep playing more matches and get used to that feeling, especially on a really big stage.

"Honestly, if I get past the disappointment, I feel pretty proud of myself to have gotten that many opportunities while still feeling like I could have played much better."

Data Debrief: Fifth time's the charm?

Muchova is one of nine players to have defeated five former world number ones at grand slam events.

However, out of those, she is the only active player yet to win a major or a WTA 1000 title. Will that change in New York?

Naomi Osaka secured a long-awaited victory over a top-10 opponent after dispatching Jelena Ostapenko at the US Open on Tuesday.

World number 88 Osaka scored a 6-3 6-2 victory against Ostapenko for her first top-10 win in four-and-a-half years.

Osaka has now won 23 of her 28 matches at the US Open, at an 82% win ratio, which only Bianca Andreescu (86%) can better among current players with 10 or more main-draw matches at the tournament.

The four-time major winner was reduced to tears after downing the 10th seed in New York.

"I was trying not to cry when I was walking out too," Osaka said in her on-court interview. "I remember last year I was watching Coco [Gauff] play and I so badly wanted to step on these courts again and I didn't know if I could.

"I didn't know athletically, physically if I was able to. Just to win this match and just to be in this atmosphere means so much to me, so thank you."

Osaka, who won 39 of her 50 service points and held her serve throughout, needed three match points to move into the second round.

"I mean it was stressful, she was hitting some really good shots and I just told myself like, keep going, keep fighting for every point and maybe you'll have an opportunity," she added. 

"Eventually I did but then I looked up and then I saw so many faces so I was like, woah."

The unseeded Karolina Muchova awaits on Thursday for the Japanese star after her first-round triumph.

Emma Raducanu says she is always ready to "do things a little bit differently" as she prepares for the US Open.

The 21-year-old is set to play just her second match at Flushing Meadows since winning the grand slam as a teenage qualifier in 2021.

She will face American Sofia Kenin in the first round, with Jessica Pegula a potential second-round opponent if she gets through.

Raducanu has only played one tournament since being knocked out in the fourth round at Wimbledon, opting to miss the Olympics, as she continues to ease herself back into regular action after her long injury lay-off.

She reached the quarter-finals in Washington, going out to eventual champion Paula Badosa, but chose not to play in Toronto before deciding against qualifying for Cincinnati.

"I really wanted to play in Toronto, especially because I was born there, but the turnaround was too tight for qualifying," she told BBC Sport.

"I would have had to play on Sunday, and I finished [in Washington] late Friday night, so flying there and adjusting, I just felt was too tight.

"Otherwise, I just always do things a little bit differently.

"[In Cincinnati] I would have pretty much had to wait around just for one tournament in qualies and then another week off before the US Open - so I think it was a better decision we all made to just go back and work on things there."

Meanwhile, Naomi Osaka is hoping familiar surroundings will help to boost her confidence after a tough run in 2024.

Since returning from a 15-month maternity break in January, Osaka has struggled to recapture her top form, and in her most recent outing in Cincinnati, she was knocked out in the second round of qualifying.

Having won the US Open in 2018 and 2020, the 26-year-old believes being back in the city she grew up in will help her find her footing.

"I feel like, throughout the year, I have had really hard matches, and it kind of dipped my confidence a little," Osaka told reporters on Saturday.

"I do think coming to this specific tournament helps me out. But also, whenever I step foot here, I don't really think about the two tournaments I won.

"I just think about how I felt when I was a kid, because I did grow up coming here, and I have such vivid memories of watching my favourite players. It's more of a childhood nostalgia that I really enjoy."

Two-time champion Naomi Osaka and fellow former winners Stan Wawrinka, Dominic Thiem and Bianca Andreescu were given wildcards for the upcoming US Open. 

Osaka, who lost in the final round of qualifying for the Cincinnati Open, won the first of her four grand slam titles at Flushing Meadows in 2018, winning again two years later. 

The former world number one returned to the tour this season after giving birth last year, but has struggled to find the form that led her to climb to the top of the rankings. 

The Japanese is now ranked 90th in the WTA rankings, with her best finishes coming in Doha and 's-Hertogenbosch where she reached the quarter-finals in both. 

She will be joined in the women's singles by Canada's Andreescu, who was crowned the US Open champion after her win over Serena Williams in 2019. 

The 24-year-old returned to action this year after missing nine months due to a back injury and reached the French Open third round in her first event back.

Meanwhile, Thiem headlines the wildcards in the men's singles in what will be the final grand slam of his career after confirming he will retire at the end of the season. 

The Austrian won the US Open in 2020 in an epic five-match thriller against Alexander Zverev, but has failed to his best form after sustaining a wrist injury three years ago. 

Also returning thanks to a wildcard is Wawrinka, eight years on from when he claimed the title in New York against Novak Djokovic at Flushing Meadows. 

The 39-year-old's triumph in the United States was the latest of his three career grand slams, having previously prevailed at the Australian Open and French Open. 

Naomi Osaka said she still does not feel like herself eight months into her comeback season following her latest defeat at the Cincinnati Open. 

Osaka was beaten in three sets by Ashlyn Krueger in the second round of qualifying for the event ahead of the final grand slam of the year at the US Open. 

The former world number one also lost in her first match of the Paris Olympics to Angelique Kerber and was beaten in the last 32 of the Canadian Open last week. 

Osaka was left puzzled by her lack of accuracy and power in her most recent loss, explaining her current form is having an affect on her mentally. 

"My biggest issue currently isn't losses though, my biggest issue is that I don't feel like I'm in my body," Osaka wrote on Instagram on Tuesday.

"It's a strange feeling, missing balls I shouldn't miss, hitting balls softer than I remember I used to.

"I try to tell myself, 'It's fine you're doing great. Just get through this one and keep pushing', mentally it's really draining through.

"Internally, I hear myself screaming, 'What the hell is happening?!?!'"

Osaka returned to action in January after a 15-month break during which she gave birth to her daughter. 

The Japanese is now ranked 90th in the WTA rankings, with her best finishes coming in Doha and 's-Hertogenbosch where she reached the quarter-finals in both. 

"I've played a handful of matches this year that I felt like I was myself and I know this moment is probably just a small phase from all the new transitions (clay, grass, clay, hard), however the only feeling I could liken how I feel right now to is being post-partum," Osaka said.

"That scares me because I've been playing tennis since I was three, the racket should feel like an extension of my hand."

Osaka's next event will be at Flushing Meadows, a stadium where she triumphed in 2018 and 2020, but added she did not understand why everything about her game felt brand new again. 

"This should be as simple as breathing to me, but it's not," she added. "I genuinely did not give myself grace for that fact until just now."

Naomi Osaka crashed out of the Canadian Open with a straight-sets defeat to Elise Mertens in the second round on Thursday.

The Belgian held her nerve for her second win over Osaka this year, beating her 6-3 6-4 in Toronto to set up a meeting with Liudmila Samsonova in the round of 16.

Osaka was caught out by making errors from the baseline and failed to gain any momentum as her preparation for the US Open took a hit with her early exit.

Despite the defeat, the former world number one remained upbeat about her performance as she looks to build on this result.

"I feel like I could have put a bit more on the court, a bit more from the baseline shots," Osaka said. "I got a bit caught up in the idea of being consistent and staying in the exchanges, I don't know.

"I'm happy with how I fought despite not winning, but I feel like I learned a lot.

"Unfortunately, I have always suffered a lot from my perfectionism, and I also tend to doubt myself a lot, but I think it's necessary to go through this process and have tough losses from which you can learn a lot about yourself.

"I know there will be many tough defeats like this one, but hopefully, I hope to be back in the top ten soon." 

Data Debrief: Fight fizzles out

Osaka struggled to gain a foothold in the match, losing her serve four times while only earning two breaks in return. 

She won just 37% of her second serve points (10/27) and failed to win more than two games in a row as Mertens edged out of her reach. 

Naomi Osaka said her straight-sets victory over Ons Jabeur in the Canadian Open demonstrates her growing confidence.

The four-time grand slam champion defeated world number 16 Jabeur 6-3 6-1 in her first-round match in Toronto.

Osaka’s victory follows her early exit in the Olympics where she lost in straight sets to Germany’s Angelique Kerber last month at Roland-Garros.

Away from the clay courts, the Japanese player felt the surface and her opponent brought out the best in her in Canada.

“Everyone knows I really love hard court,” said Osaka. “So I don’t know, I wasn’t really thinking too much.

"It felt very instinctual and honestly when I play the best players like Ons I tend to play better."

Now, Osaka believes she is beginning to build momentum again after her hiatus.

“I think if you’ve been following my journey a little, I go through mountains and hills. But now I’m feeling quite confident in myself as a person and a player and I think that showed a little,” she explained.

“Hopefully I can continue to play a lot more matches, but I think I just really love playing tennis and it’s been an honour to play such a great match in front of everyone.”

Naomi Osaka put her Paris Olympics disappointment behind her as she eased to the next round of the Canadian Open in a straight-sets win over Ons Jabeur.

Osaka fell at the first hurdle to Angelique Kerber at Roland-Garros last month, but was back to her best as she emerged a 6-3 6-1 victor in Toronto. 

The four-time grand slam champion wasted no time in stamping her authority on proceedings, earning a two break points to take a 3-0 lead early on. 

And that would prove decisive, with the world number 95 seeing out the rest of her service games, closing out the first set with a love game. 

Jabeur would have no response to Osaka's stunning display, with the Japanese finding another pivotal break before winning the remaining three games to confirm the win. 

Osaka will face Elise Mertens in the round of 32 after the Belgian beat Katie Volynets in straight sets earlier in the day. 

Data Debrief: Osaka over Olympics disappointment

Having suffered disappointment in Paris, Osaka responded in emphatic style upon her return to the court and will want to continue that momentum moving forward. 

Osaka converted all three of the break points she had, winning all eight of her service games. 

It proved to be a difficult day at the office for Jabeur, who uncharacteristcally served seven double faults throughout the contest compared to Osaka's four. 

Naomi Osaka quipped she has been "stalking" Iga Swiatek after her first-round defeat at the Olympics.

Four-time grand slam champion Osaka, now ranked at world number 95, lost in straight sets to Germany's Angelique Kerber on Court Philippe-Chatrier in Paris.

Former world number one Osaka returned to tennis earlier this year after giving birth in July 2023.

Now she hopes she can climb back up the rankings by watching others on the tour, and world number one Swiatek has been high on her list.

"I was stalking Iga. I was watching her practice at the Olympics, and for me, that's something I want to do more, watch the great players, because there's always something I can pick up on," Osaka told reporters ahead of the Canadian Open.

"I know she has one of the best footwork skills on the WTA. I'm just trying to copy a little bit." 

The Japanese player found her Olympics experience more enjoyable than three years ago at her home Games, where she lit the Olympic flame.

"I would say in Tokyo [2020], I was definitely really stressed. In Paris, I felt a lot more fun. And obviously there were spectators there, so it was a lot different," reflected the 26-year-old.

"In Paris, I felt a lot more fun. And obviously there were spectators there, so it was a lot different. But I didn't stay in the village, so that is something that I regret a little bit, not to have the full experience. Overall, I think it was it was fun. Hopefully, I can play in LA [in 2028]."

Osaka has naturally faced challenges in her return to sport following pregnancy, which has made her presence at the Olympics a year on from giving birth impressive in itself.

"Honestly, after pregnancy, I wasn't really sure how my movement would be," said Osaka.

"I remember being on the track at UCLA [University of California, Los Angeles] and almost crying in frustration because I felt like I couldn't run as fast as I wanted to.

"It felt like I was in a body suit that was not performing the way I wanted. Now, to be here, is a really incredible achievement."

Having a daughter has also given Osaka a new outlook on her sport.

"I lost in the Olympics, I was, of course, really devastated," she explained. "But I was just surrounded by my team.

"Then I went back home, and I saw my daughter, and she's just happy to be alive. She's happy that I'm her mom and it just gave me a lot of motivation.

"I feel like when I was younger I was searching for my purpose in life. The way I grew up, my only purpose was tennis. Then obviously taking the year that I had as a break, it let me see that there are so many different things in life and it's a beautiful world."

Angelique Kerber breezed into the second round at the Paris Olympic Games with a straight-sets win over Naomi Osaka.

In her final tournament, the German kept her hopes of going out on a high alive, getting a 7-5 6-3 victory in just 69 minutes at the end of a rainy opening day at Roland Garros.

Osaka started strongly, racing into a 3-1 lead, but Kerber fought back and eventually got the vital break in the penultimate game of the set to edge in front.

The two were evenly matched again at the start of the second, but Osaka struggled to maintain her high level and lost her serve twice at the end as Kerber's four-game winning run carried her over the line.

Kerber will now face Jaqueline Cristian of Romania in the second round.

Data Debrief: Going for gold

Kerber won a silver medal in singles at Rio 2016, and she is looking to sign off her glittering career by going one better in Paris.

She asserted her dominance in the second set, particularly, winning 13 of 14 points when she got her first delivery into play.

Kerber also bows out holding a 5-2 head-to-head record over Osaka, who once again struggled on clay.

Rafael Nadal could face Novak Djokovic in a heavyweight second-round match at the Paris Olympic Games after the draws for the tennis tournaments were made on Thursday.

Nadal is widely expected to retire from tennis later this year, with the Olympics set to represent his swansong at Roland-Garros, where he has won 14 French Open titles.

He will play in both the singles and doubles tournaments, partnering current French Open and Wimbledon champion Carlos Alcaraz for the latter competition.

Nadal and Alcaraz will face Argentina's fourth-seeded pair Maximo Gonzalez and Andres Molteni in a difficult first-round matchup in the doubles tournament.

Nadal is one of just two players to have won Olympic gold in both singles and doubles since the sport returned to the Games in 1988, doing so at Beijing 2008 (singles) and Rio 2016 (doubles) – Nicolas Massu triumphed over both events at Athens 2004.

In the singles, Nadal will take on Hungary's Marton Fucsovics in the opening round, and the prize could be a second-round date with Djokovic, who faces Australian Matthew Ebden first.

They are on the same side of the draw as third seed Alexander Zverev, who faces Jaume Munar first, and seventh seed Taylor Fritz, who opens against Alexander Bublik.

On the opposite side of the bracket, Alcaraz will start his campaign against Hady Habib, with Britain's Cameron Norrie a potential second-round opponent.

Fourth seed Daniil Medvedev faces Rinky Hijikata in his first match, while fifth seed Alex de Minaur is a potential quarter-final opponent for Alcaraz.

Britain's Andy Murray withdrew from the singles event to concentrate on his doubles bid alongside Dan Evans on Thursday, and the duo will face Kei Nishikori and Taro Daniel of Japan first.

Should they advance, home favourites Arthur Fils and Ugo Humbert could await in round two, with Taylor Fritz and Tommy Paul potential quarter-final foes, though the Americans will have to overcome Canada's Milos Raonic and Felix Auger Aliassime to get that far.

Murray and Evans cannot face Nadal and Alcaraz until the final. 

Iga Swiatek is the strong favourite in the women's draw, having won four French Open titles on the Paris clay. Romania's Irina-Camelia Begu is her round-one opponent.

On her same side of the draw, there is a huge round-one clash between Naomi Osaka and 2016 silver medallist Angelique Kerber, who announced on Thursday that she will retire after the Games.

Elena Rybakina and Danielle Collins are also on that side of the draw, while Coco Gauff starts against Ajla Tomljanovic on the opposite side of the bracket.