Petra Kvitova made a shaky start but found her attacking verve midway through the match to beat world No.1 Caroline Wozniacki in their Qatar Open semi-final.
The Czech prevailed 3-6 7-6 (7-3) 7-5 to set up a final with Spain's Garbine Muguruza.
Kvitova, 27, who lost the opening set tamely and looked in some trouble while trailing 3-1 in the second, fought back in style to clinch her fourth-straight victory over the Dane.
"I don't know what happened. I was a little crazy in my mind and I was playing everywhere and not to the court," twice Wimbledon champion Kvitova said in a court-side interview.
"I tried to calm myself down a little bit in the second set. Even though I was losing, I was trying to get back somehow.
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"When I was down 3-1 I was really angry with myself and I tried to hit some winners.
Kvitova, who made 59 unforced errors including 11 double faults, hit 50 winners.
Having dragged the second set into a tiebreaker which she edged, the battling Czech quickly switched gears and attacked her opponent relentlessly to prevail in the decider.
Up next for Kvitova is world No.4 Muguruza, who enjoyed the day off after her semi-final opponent Simona Halep pulled out of the tournament with a right foot injury after her quarter-final win on Friday.
"She (Muguruza) had a day off today. Who knows if it's an advantage or not, but I had a great match," Kvitova said.
"It was great for my confidence turning the match around."
World No.21 Kvitova won the St Petersburg title earlier this month and a second success of the season would give her a shot at returning to the top 10.
