SINGAPORE - US Open champion Naomi Osaka had already done disappointment by the time she arrived for her post-loss press conference at the BNP Paribas WTA Finals Singapore presented by SC Global.

“I took my five minutes of being really sad,” she said after a 7-5, 4-6, 6-1 defeat to 2017 US Open winner Sloane Stephens. “From then, I don't know. I just tried to think that you learn more when you lose, so what can I learn from this match and try to apply it to the next match?

“All the players that you play here are the best in the world, and you expect to have a really hard battle every match. In a way, you can only get better every match you play.”

While Osaka aims to improve her comfort level with the Singapore Indoor Stadium’s Center Court - admitting to feeling out of rhythm for large swaths of the two hour, 24 minute epic - there wasn’t much the Japanese star would change about her WTA Finals debut.

"I think it's cool that you can keep going even after you lose. I think that this tournament is really special in that way. The fact that you get another chance to learn from your mistakes and apply it in the matches going on is really good."

- Naomi Osaka

“Usually after I lose, I have very specific things that I think would have changed the match. But I don't really have any regrets for me. This entire match was a really hard battle. I think she played really well, and I think she deserved to win the match.”

Two things she does hope to address: her “disappointing” first serve percentage, and her attitude, apologizing for a few emotional outbursts after the match.

“That was something I'm not really proud of. I feel like for me I play better when no one knows what I'm thinking. But it's also something I am learning how to do, because it's not like I have been consistently able to do that. It shows like my ups and downs.”

It was the first match for both Osaka and Stephens, who spent Friday’s Gala evening getting to know one another before finding out they’d been drawn into the same round robin group.

“I'd never really spoken to her before, so I was, like, ‘Okay, maybe I should talk to her. She's sitting right next to me,’” Stephens recalled on Monday. “I'd say Naomi, out of everyone, is like the quietest.

“We took some selfies. It's different when you don't see a person that much, don't speak to them that much. Obviously she's a great girl, a really nice person, and I'm glad we got that little seven minutes or so to kind of chitchat.

“I don't really go out of my way to be besties with everyone. Obviously there is only eight people here, eight players, so if one of them is sitting next to you, it's probably a good time to have a little talk.”

Osaka will next face another familiar opponent, at least in the on-court sense, in either top seed Angelique Kerber or No.8 seed Kiki Bertens.

“I played Kerber, like, 100 million times,” she joked, later clarifying she was not, in fact, a “Kerber expert.”

“We both know how we're gonna play. I know she's a Grand Slam champion. She's gonna play amazing, and I have to expect that the match is going to be very difficult. I have practiced with Kiki before, and I know that she's a great player, as well.

“At this level, at this tournament, everyone plays really well and everyone wants to win. So I just have to expect, like, really hard matches all the time.”