Naomi Osaka began the defence of her Pan Pacific Open crown with a quick win after opponent Daria Saville was forced to retire in just the second game.

Four-time grand slam champion Osaka won the opening game, before Saville was unable to continue due to a scary-looking injury to her left knee.

The former world number one will now face a second round match with world number 16 Beatriz Haddad Maia, who eased to a straight sets victory over Yuki Naito.

Karolina Pliskova secured her place in the next round in Tokyo with a 6-2 6-1 demolition of Isabella Shinikova, while Zhang Shuai will face second seed Caroline Garcia on Wednesday after overcoming Mai Hontama in two sets.

In Seoul, Jelena Ostapenko's hopes of repeating her 2017 heroics at the Korea Open are still alive after the number one seed narrowly beat 19-year-old Jeong Bo-young.

The world number 19 looked to be cruising after the opening set, but the unheralded South Korean hit back in the second and took it to a tie-break in the third, before Ostapenko's class showed as she won the crucial tie-break 7-2.

Elsewhere, 2021's beaten finalist Kristina Mladenovic saw off wildcard Park So-hyun 6-4 4-6 6-3, while second seed Ekaterina Alexandrova overcame a worrying second set to beat Asia Muhammad 6-1 3-6 6-1.

Wimbledon semi-finalist Tatjana Maria is also safely through to the second round after a tight 7-6 (7-5) 7-6 (7-5) triumph over Eugenie Bouchard.

Coco Gauff lost her second French Open final of the weekend as the teenager and Jessica Pegula were beaten by Caroline Garcia and Kristina Mladenovic in the women's doubles.

Gauff was defeated in straight sets on Saturday by world number one Iga Swiatek in her maiden grand slam final at Roland Garros.

The 18-year-old and her fellow American Pegula started well on Sunday, taking the first set before their French opponents stormed back to win 2-6 6-3 6-2 on Court Philippe-Chatrier.

An early break from Gauff and Pegula gave the number eight seeds the advantage, before another in the seventh game allowed them to serve out the opening set.

However, the experienced Garcia and Mladenovic found several more gears to race out into a 4-0 lead in the second set.

Gauff and Pegula - who was also beaten by Swiatek in the quarter-finals of the singles' event in Paris - came back to 3-4, but were broken again and the French duo grasped the chance to level the match.

The decider was one-sided, with Garcia and Mladenovic again taking a 4-0 lead, before eventually serving out to win as the 2016 champions were able to repeat the trick six years later in front of a delighted home crowd.

Mladenovic has now celebrated four doubles triumphs in her home grand slam - two with Garcia and as many with Timea Babos. This was Garcia's second success.

Sloane Stephens ended her losing run to start the year with a hard-fought three-set win over France's Oceane Dodin in the first round of the Miami Open on Wednesday.

Former US Open champion Stephens, ranked 49th in the world, defeated Dodin 6-7 (6-8) 6-4 6-2.

Stephens progresses to the second round where the top seeds, including top three Ash Barty, Naomi Osaka and Simona Halep, will be introduced and she will face 28th seed Amanda Anisimova.

Danielle Collins, Wang Qiang, Alize Cornet and Caroline Garcia were among the other winners on Wednesday, while Svetlana Kuznetsova bowed out.

SLOANE FIGHTBACK

Stephens had endured a dismal start to 2021, enduring an 0-4 win-loss record to begin the year.

The 28-year-old American was made to do it the hard way against Dodin on Wednesday, dropping the first set in a tie-break.

Stephens improved on her return in the second set, winning 73 per cent of points off Dodin's second serve before running away with the match in the last.

"It's been a rough one for me lately, so I'm really pleased to get through that, fight my way through it and make it happen somehow," Stephens said post-match.

FORMER MAJOR WINNER GONE

Two-time grand slam winner Kuznetsova was the major first-round casualty, going down 2-6 6-2 6-1 to France's Alize Cornet.

Kuznetsova, who is now ranked 35th in the world, bows out with Cornet to face ninth seed Petra Kvitova.

Collins got past France's Kristina Mladenovic 6-3 6-3 with the 40th-ranked American setting up a second-round clash with 32nd seed Veronika Kudermetova.

Wang, ranked 38th in the world, also progressed despite dropping a set in a 6-1 3-6 6-3 win over Spanish qualifier Aliona Bolsova.

SECOND-ROUND MATCH-UPS

The round of 64 will commence on Thursday, with third seed Halep to face Garcia who got past another Romanian, Mihaela Buzarnescu 6-1 6-2.

Top seed Barty will be in action against Slovakia's Kristina Kucova, while fourth seed Sofia Kenin will take on former top-10 player Andrea Petkovic.

Second seed Osaka has an assignment against 77th-ranked Australian Ajla Tomljanovic, while 14th seed Victoria Azarenka is already into the third round with opponent Laura Siegemund withdrawing after her win on Tuesday.

Madison Keys is intent on giving Maria Sakkari a second-round test after marking her first WTA Tour appearance since September with a clinical win at the Qatar Open.

American world number 19 Keys, who reached the US Open final in 2017, had not played on tour since losing to Zhang Shuai in the first round of the French Open in late September – she was ruled out of the Australian swing of this season after a positive coronavirus test.

But Keys roared back to action with a thumping 6-4 6-1 victory over Belinda Bencic on Tuesday, the Swiss who last week reached the Adelaide International final.

"I'm really happy with how I came out and played today," Keys said. "I'm a little bit surprised with myself but hoping to keep the momentum going."

Sakkari promises to pose a tricky test for Keys, who is unseeded this week, given the Greek player dropped only three games in her opening win over Mayar Sherif and has shown bright early-season form.

World number 23 Elena Rybakina tripped up in the first round after the Moscow-born Kazakh player lost 7-6 (9-7) 7-6 (7-5) to Germany's 56th-ranked Laura Siegemund at the WTA Premier event.

Jessie Pegula, Anastasia Pavlyuchenkova, Ons Jabeur and Misaki Doi also scored straight-sets victories in Doha.

At the Lyon Open, French players Caroline Garcia and Kristina Mladenovic were both pushed to three sets before inking their places in the last 16.

Third seed Garcia edged compatriot Oceane Dodin 6-2 2-6 6-3, while fourth seed Mladenovic scrambled for a 5-7 7-5 6-2 win over Romanian Mihaela Buzarnescu.

Former Wimbledon runner-up Eugenie Bouchard, in on a wildcard, was bounced out 7-6 (9-7) 6-2 by Aliaksandra Sasnovich, the world number 96 from Belarus.

Ash Barty may have her focus on winning the Australian Open right now but suggested a career change could be on the cards in the future.  

The world number one made sure she will still be competing during the second week of the tournament in Melbourne by beating Ekaterina Alexandrova in straight sets.  

But, having played international cricket for Australia before switching to tennis, could the multi-talented Barty be considering trying another sport?  

Elsewhere in Saturday's action, Karolina Pliskova lost her cool – and also a couple of rackets – as she slipped to defeat against the impressive Karolina Muchova in an empty Rod Laver Arena, with fans not able to be present due to a five-day lockdown in the state of Victoria.

Elina Svitolina had no such problems in her third-round match, while Elise Mertens was victorious in just over an hour against Belinda Bencic. Jennifer Brady ended Slovenian qualifier Kaja Juvan's run in the first grand slam of the year.

AUSSIE RULES, OK? 

After winning 6-2 6-4 without ever needing to be at her peak, Barty was cheekily asked by former doubles partner Casey Dellacqua – now working in the media – whether she may be set to switch paths again, once her tennis career has come to an end.  

Australian rules football was the answer – but Dellacqua maybe got more than she bargained for from her former playing partner during the on-court interview. 

"I thought it was our deal, we're going to AFLW. It's ABCD [the nickname for the pairing from their doubles career]. We come as a package, and I know we will be going to the [Richmond] Tigers that is for sure," Barty said. "You can't go to Carlton. You have to come to the 'Tiges' with me."

Dellacqua replied: "I need to get out there and start practicing some kicking, but you are good. I would love to do that one day." 

For Barty, though, the next challenge facing her is Shelby Rogers, who knocked out 21st seed Anett Kontaveit during the evening session.  

MAKING A RACKET 

A disgruntled Pliskova was not impressed when punished for smashing up a racket during her match with compatriot Muchova. 

Having received a warning when throwing a racket to the floor during the course of the final game in the opening set, the sixth seed then vented her frustration again on another while in the players' tunnel.  

An official witnessed the incident and reported it to chair umpire Alison Hughes, who punished the Czech with a point penalty before she began serving to open the second set.  

"It's off court, I'm allowed to do what I want," Pliskova insisted when querying the decision to the official. She would go on to hold before recording two successive breaks, yet somehow failed to force a decider.  

Muchova rallied from 5-0 down in sensational fashion, winning seven games on the spin to triumph 7-5 7-5 to make it through to the last 16.

CONTRASTING PROGRESS FOR SEEDS

Svitolina has still yet to drop a set in the tournament after overcoming 26th seed Yulia Putintseva by a 6-4 6-0 scoreline.  

The fifth seed was twice down a break in the first set but, after eventually coming out on top to take a 1-0 lead, breezed through the second in a hurry.  

"She has a very different game style from what I played my last two rounds, so it wasn't easy at the beginning to adjust," Svitolina said. "As soon as I was feeling better, I just stepped my game, and it was quite a comfortable win after." 

Next up will be Jessica Pegula, who is through to the fourth round at a slam for the first time in her career after thrashing Kristina Mladenovic 6-2 6-1.  

There was also success for another American in the main draw, Brady defeating Juvan in straight sets. Her reward is a clash with Donna Vekic, the 28th seed having to save a match point before eventually seeing off Kaia Kanepi 5-7 7-6 (7-2) 6-4 after two hours and 38 minutes on court.