Naomi Osaka delivered a withering assessment of her performance after she was knocked out of the Brisbane International at the semi-final stage.
The reigning US Open champion and world number five suffered a surprise 6-2 6-4 defeat to Lesia Tsurenko, who set up a final showdown with Karolina Pliskova after the Czech fifth seed dispatched Croatia's Donna Vekic 6-3 6-4.
Much of the attention fell on Osaka, though, who was at a loss to explain why she struggled for fluency against her Ukrainian opponent.
The Japanese said in quotes on the WTA Tour: "If I'm being really frank, I just feel like I had the worst attitude. 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.
"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 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."
Bianca Andreescu reached her first singles final on the WTA Tour as she claimed another upset win at the ASB Classic in Auckland.
The Canadian qualifier had already seen off top seed Caroline Wozniacki and seven-time grand slam champion Venus Williams this week, and she added third seed Hsieh Su-wei to her victims list.
Andreescu clinched a comfortable 6-3 6-3 victory over her Taiwanese opponent to book a final date against second seed Julia Gorges, with the German overcoming Slovakia's Viktoria Kuzmova 6-1 7-6 (8/6).
World number 13 Aryna Sabalenka overcame Yafan Wang and Alison Riske to bag the Shenzhen Open title.
The Belarusian thrashed Chinese opponent Yafan 6-2 6-1 in the last four stage before battling back to see off America's Riske 4-6 7-6 (7/2) 6-3 in the final.
Riske had breezed her way into the showpiece when Russian opponent Vera Zvonareva retired as she trailed 6-0 1-0.
