World number one Naomi Osaka survived another early scare to reach the third round of the French Open.

Japan's Osaka, 21, overcame a poor start to beat two-time Grand Slam champion Victoria Azarenka 4-6 7-5 6-3.

Osaka is chasing her third successive Grand Slam title having won the 2018 US Open and the Australian Open earlier this year.

She will play Greece's Maria Sakkari or the Czech Republic's Katerina Siniakova in the next round.

"I was lucky enough to play her (Azarenka) twice before this and I knew she was playing really well," said Osaka.

"It was unfortunate that this was a second-round match but I am happy I won."

Asked if she is as calm on the inside as she looks on court, she added: "No. I choked on this side (at 5-1) and almost choked on the other side (at 5-3). I am very emotional."

Osaka struggled in the early stages against world number 43 Azarenka, of Belarus, just as she did in the first round against Anna Karolina Schmiedlova when she failed to register a game.

She hit 15 unforced errors in the opening set on Lenglen court as Azarenka, 29, dominated to go 5-1 up.

From there, Osaka - who reached the third round at Roland Garros 12 months ago - started to find her rhythm, breaking Azarenka's serve to move within one game of her opponent but Azarenka coolly served out the first set.

The second set proved a much closer affair, taking until the fifth game for a serve to be broken as Azarenka went 3-2 up. That came after Osaka had scuppered three break points in the fourth game.

Azarenka went on to go 4-2 up but Osaka was able to claw the set back, taking it 7-5 on her fourth set point.

Former world number one Azarenka took an 11-minute break before the deciding set commenced, but it proved little help as Osaka raced into a 5-1 lead, her performance a far cry from that of the first set.

Azarenka mounted her own comeback, winning the next two games, but Osaka was able to capitalise on her second match point to seal victory.