World number one Naomi Osaka on Saturday launched her Indian Wells title defense with a 6-3, 6-4 victory over 65th-ranked Kristina Mladenovic of France.

Osaka, whose second straight Grand Slam title at the Australian Open in January propelled her to the top of the rankings, avenged a loss to Mladenovic in Dubai last month in her first match since she lifted the trophy in Melbourne.

It wasn’t all smooth sailing as Osaka was broken when serving for the match at 5-2 in the second.

After Mladenovic held serve to narrow the deficit to 5-4, the Japanese player faced another break point before wrapping up the match after one hour and 21 minutes.

“I’ve never been a defending champion before – that’s new and I was really nervous,” said Osaka, whose first WTA title at Indian Wells last year launched a 2018 campaign that would eventually include her first Grand Slam crown at the US Open.

Osaka next faces Danielle Collins, the 25th-seeded American who beat Belgian Kirsten Flipkens, 6-4, 6-1.

Venus comeback

Seven-time Grand Slam champion Venus Williams rallied from a set and two breaks down to topple third-seeded Petra Kvitova 4-6, 7-5, 6-4 on Saturday and reach the third round at Indian Wells.

“Today I just fought and tried my hardest,” said Williams, currently ranked 36th in the world.

“Honestly, a double break is not ideal against a great server, especially a left-handed server.

“A lot of it is just being in the moment. And I think I created some opportunities. I had some good points. I think she had a few tight points, and here we are.”

She booked a third-round clash with fellow American Christina McHale, a 6-4, 3-6, 6-4 winner over 30th-seeded Russian Anastasia Pavlyuchenkova.

Two-time Wimbledon champion Kvitova, who was runner-up to Naomi Osaka at the Australian Open in January, also reached the final in Dubai last month.

The Czech appeared to have taken control of the stadium court slugfest when she broke Williams for a 4-3 lead in the third.

But Williams immediately broke back and Kvitova soon found herself serving to save the match. She took a 40-15 lead in the final game, but two double faults, followed by a lucky netcord bounce for Williams gave the American a match point and Kvitova sailed a ball long to end matters after two hours and 27 minutes - sparking an ebullient celebration from Williams.

“Having to play down the whole match and to be able to get that,” Williams said of her emotion. “It was just a fun moment.”

Williams pulled off the unlikely comeback despite failing to produce a single ace although she said her varying serve speeds were “what I needed to do”.

She was broken four times, but proved more consistent in the bruising baseline rallies.

Kvitova fired 10 aces, but also had 10 double faults and while the Czech fired 38 winners to Williams’s 15, her 56 unforced errors were more than double the American’s 25.

“It was such a weird match,” Kvitova said, calling it her worst of the year. “I took the first set. Suddenly I was leading in the second, but somehow I just gave her a chance again to be back in the match, and she took it.

“Suddenly, she just started to play better, I started to play worse ... I was so frustrated with myself from the half of the second set to the end, which shouldn’t happen to me.

“I really played bad,” she said, “and in the end of the match she definitely played better than me.

Dusk was arriving in the California desert when Williams and Kvitova departed the court.

Elsewhere on Saturday, fifth-seeded Karolina Pliskova shook off a slow start to defeat Japanese qualifier Misaki Doi 6-7 (4/7), 6-1, 6-1.

Pliskova next faces another qualifier, Belgian Ysaline Bonaventure, who defeated 28th-seeded Donna Vekic of Croatia 1-6, 7-6 (7/5), 6-4.

Eighth-seeded German Angelique Kerber eased into the third round with a 6-0, 6-2 victory over Kazakhstan’s Yulia Putintseva.