Flavia Pennetta shocked Li Na in the semi-finals of the BNP Paribas Open in Indian Wells on Friday, beating the Australian Open champion 7-6 (7-5), 6-3 to set up a title clash with Agnieszka Radwanska.
Li, the Chinese world number two who was the top seed in the elite WTA premier event, had pounded winners past Pennetta in a crushing 6-2, 6-2 victory in the Australian Open quarter-finals in January.
But her bid to reach the final in the California desert for the first time was hampered by a welter of forehand errors and nine double faults.
“I don’t think I was playing bad,” Li said. “I think it was a pretty high level match. Some points I was feeling I still had a chance but on the more important points I got double faults.”
Eight of her nine double faults came in the opening set, including one to hand Pennetta the set on her second set point in the tiebreaker.
Li put the double faults down to a change in the mechanics of her serve, and said it was something she would just have to fight through.