Agnieszka Radwanska's stunning start to 2013 came to a stuttering halt at the Australian Open as she suffered a straight-sets loss to Li Na.
Radwanska had won 13 successive matches, collecting the WTA Tour titles in Auckland and Sydney along the way.
However Li's all-or-nothing style of play paid dividends as she toppled the fourth seed 7-5 6-3 to book a semi-final showdown with Maria Sharapova.
It was a high-risk strategy from Li, who made 40 unforced errors but was able to break Radwanska twice in the opening set.
Radwanka fashioned out another break of her own at the start of the second, but a run of five successive games from Li took the sixth seed to the brink of her third semi-final in Melbourne.
And although Radwanska held serve, Li overcame a few wobbles to advance after one hour and 42 minutes.
"I really don't know what it is here," said LI. "It seems whenever I come down here my results are always quite consistent, no big setbacks or anything.
"I'm not sure whether it's the winter training but it does seem like I'm just better at this tournament.
"With the Australian Open, it's like coming back and thinking, 'all my old friends are here'.
"Agnieszka's a tough player. I felt like I was against a wall today. She can hit everywhere, but without any mistakes.
"I felt it was just very tough. You have to focus on every shot. Not every point, every shot. If you hit like slow or like short one, she'll attack."