Naomi Osaka revealed she "felt like a challenger" during her second-round French Open clash with Victoria Azarenka.

World number one Osaka was forced to battle back from a set and a break down for the second time in two matches at Roland Garros as she defeated former top-ranked player Azarenka 4-6 7-5 6-3.

The Japanese has won the past two grand slams, but playing an opponent who twice claimed the Australian Open in 2012 and 2013, she claimed Azarenka felt like a scalp.

"I kind of felt like a challenger," Osaka told a news conference. "I know she went to the semis here before, so obviously she has a lot more experience here.

"She won grand slams and she was number one way before I was. I'm still kind of new at this. I don't know.

"For me, I have always wanted to play her while she was at her best. I know the last time I played her, in Rome, it definitely wasn't close, so I woke up excited today.

"Then I got really nervous - and then it got better."

Anna Karolina Schmiedlova had also pushed Osaka all the way in her opening match and the 21-year-old actually felt as if she played well against Azarenka despite facing a similar result.

"I think, for me, I feel like I didn't dip at all during this match," Osaka said. "[Azarenka] was just playing so well.

"I was just waiting for her to get a little bit tired. I think she did towards the end of the second set and the third set. That's when I just tried to really accelerate how fast I was winning the points."

It was put to Osaka that she showed calm as she battled back, yet the player disagreed, pointing to a missed opportunity late in the match that dragged out another two games.

"I choked on this side and I almost choked over there, too," she laughed on-court. "I'm very emotional, I think."