Fourth-seeded Barbora Krejcikova of the Czech Republic has beaten unseeded American Danielle Collins 3-6 7-5 6-2 to reach the finals of the WTA's San Diego Open.
Krejcikova will face wildcard Sofia Kenin, who beat qualifier Emma Navarro 6-2 5-7 6-4 in the second semi-final on Friday.
"The match was very difficult, but I never give up," said Krejcikova, also a wildcard who is ranked No.13 in the world.
"Danielle played really well in the first set, but after that I was improving with every single point, so I went for it."
After Collins controlled the first set, Krejcikova, 27, turned things around to knot the second set at five games apiece. Keeping her composure, Krejcikova then broke Collins' serve and held her own to tie the match.
Taking advantage of Collins' sudden struggle of unforced errors, Krejcikova, the 2021 French Open winner, then eased to the win over the inconsistent Collins, who reached the finals of the 2022 Australian Open before losing to Ashleigh Barty.
The San Diego Open is a WTA 500 event with a total purse of $US781,000 ($A1.2 million), including $A187,000 and 500 points in the WTA ranking for the singles champion.