BRISBANE, Australia - From every loss there is a lesson, and Naomi Osaka hopes her 6-2, 6-4 defeat to Lesia Tsurenko in the semifinals of the Brisbane International will ultimately leave a positive mark on her Australian Open campaign.

The No.2 seed struggled with her rhythm and her attitude against a superb Tsurenko, herself a US Open quarterfinalist just five months ago. 

"I felt in the warmup, too, that something was off, and I thought maybe it was the string," Osaka said. "But Sascha [Bajin] said that when he was hitting with me, he felt that I was hitting fine. 

"So I thought maybe it was just something that is in my control. But of course I felt nervous and I thought it was something that would go away, but it didn't."

Osaka served at just 45% in the opening set and did not see a break point until late in the second set. She was visibly frustrated and flat from the start of the match and 

“I don’t know why I’m flat," Osaka told Bajin during a coaching visit between sets. "I think there’s something wrong in my head. I’m putting myself in the situation that either I win the match or I die.” 

As always, Osaka offered a brutally honest assessment of her performance after the loss. 

"If I'm being really frank, I just feel like I had the worst attitude today," she said. "I feel like I didn't really know how to cope with not playing well.

"I was sulking a little bit, and there are moments that I tried not to do that. But then the ball wouldn't go in, and then I would go back to being childish and stuff."

"So, I don't know, I was sulking a little bit, and there are moments that I tried not to do that. But then the ball wouldn't go in, and then I would go back to being childish and stuff. So I think that was sort of my main problem today.

"I feel like last year I did a lot of that, and I'm trying to change it more, and I think I have, towards the end of last year. So hopefully this isn't a reoccurring thing."

"I feel like, in a way, that this experience for me is better than winning the tournament, because this helpless feeling I have, I think today I learned sort of what I have to do to, not fix it, but what I can do to improve the situation so there aren't many moments that I feel like that. 

"But, yeah, I mean I feel like today was a very valuable lesson."

"I think regarding strategies for me, I felt like I had no control over the ball today. So there are two paths that I can take. Usually, one is to hit everything. And then another one is to run everything down. And usually I pick the hitting part first and then the running later, and I think I need to switch that around."

Despite the loss, Osaka's week in Brisbane will earn her Top 4 seeding at the Australian Open. On Monday she will return to her career-high No.4 ranking after advancing to her fourth semifinal in her last five events. 

For a player who made her name by standing up to seemingly insurmountable pressure, the 21-year-old admits she's still getting a feel for her new position as a favorite. 

"It's different," Osaka said. "Before, I would just be nervous to be [in the semifinals] in a way, and now I feel nervous because I think I should win, like I'm the higher ranked player, and I feel like people expect me to win. So that's an added amount of nerves. But I feel like I'm getting used to it, hopefully."

Osaka has withdrawn from next week's Sydney International.