Petra Kvitova recovered from losing the first set to shock world number one Caroline Wozniacki and reach Sunday's Qatar Open final.
The Czech won 3-6 7-6 (7-3) 7-5 to earn her 12th successive win and set up a final against Spain's Garbine Muguruza.
It was the world number 21's third win over a top-10 player in Doha this week.
Kvitova, who won in St Petersburg two weeks ago, is continuing her comeback following six months out after a knife attack at her home in December 2016.
"I don't know what happened," she said.