World number one Naomi Osaka berated herself for a lack of maturity and focus Saturday as she fell in three sets to Taiwan's Hsieh Su-Wei in the third round of the Miami Open.
The Japanese star was left floored by the battling instincts of the world number 27, who brilliantly came from a break down in the final two sets for a 4-6, 7-6 (7/4), 6-3 victory, making amends for losing a dramatic encounter at the Australian Open earlier this year.
Osaka was dejected but, to her credit, laid bare her frustrations afterwards, insisting she lacked mental clarity and the ability to deal with the pressure of being the best in the world.
Hsieh, who completed one of the best wins of her career in two hours and 18 minutes, will now play Denmark's Caroline Wozniacki for a place in the quarter-finals and put to rest memories of being a set and 4-1 up at Melbourne before losing to eventual champion Osaka.
For two time Grand Slam winner Osaka, however, there was only severe disappointment.
Osaka had won the first set and gone up a break in the second when Hsieh rallied.
Osaka had complained about "getting too emotional" in a less than impressive second round win over Belgian Yanina Wickmayer on Friday and admitted history repeated itself at the Hard Rock Stadium just 24 hours later.
"I don't know why this is happening," the 21-year-old said.
- Just not thinking -
"It's unusual for me, I got ahead of myself. There were some times when I was returning I felt myself getting relaxed because I thought I would be able to serve it out anyway. I just need to focus more and know that I can't just turn it on or off.
"I knew it would be a tough match playing her. She is unpredictable, hitting down the line when I thought she would go cross court.
"I was kind of immature because I was thinking too much, like everything was on my racquet.
"Of course I want to win every match and I think I have dealt with people always asking me if I am going to win because I have number one next to my name.
"I thought I was doing fine with that but I guess I am not," she added. "I didn’t underestimate her, maybe overestimated myself. All the times I played her was three sets. In Australia, honestly, she should have won but I found a way to win it.
"I think there's a difference between having confidence and getting ahead of yourself," she said. "It wasn't that I had a big head, I just wasn't thinking about everything that was happening."
There were, however, some pluses for the Japanese to take moving forward to the clay court season and preparations for the French Open.
"I think my serve has improved," Osaka said. "I have been working on it and was counting on it today which is a big plus.
"She was being aggressive on my second serve which is something I need to work on.
"I think I played pretty good if I get over the fact that I lost."
Hsieh, however, knew this result was possible and her delighted reaction at the end said it all.
"She has enough experience to stay strong and you saw that," French coach Frederic Aniere, who has worked with Hsieh for the last two years and is also her boyfriend, told AFP.
"She was very happy but before this match she knew she could win. Yes it's huge, but for her it's not a big surprise."