Top seed Marion Bartoli reached her second final of the season, battling back to beat Taiwanese qualifier Chan Yung-jan 1-6, 6-3, 6-3 at the WTA Carlsbad tournament.
The world number 10 from France will square off on Sunday for the title against second seed Dominika Cibulkova, who beat Russian Nadia Petrova 7-6 (10/8), 6-1.
Bartoli passed her third consecutive three-set test, and has been on court in excess of nine hours this week.
Cibulkova, in contrast, has yet to go past two sets and said that her light workload may benefit her title bid.
"I feel really fresh and good. I didn't have a three set match and all the other girls, they played crazy long matches," said the 14th-ranked Slovak. "So I'm feeling really good for tomorrow, and I think it can be my advantage for me."
Bartoli, who has played with a sore hip, struggled mightily in the opening set and Chan, ranked 161st in the world, profited from the top seed's 20 unforced errors.
Bartoli said it wasn't, in fact, her troublesome hip that bothered her in the early going but an ankle.
"The doctor gave me some anti-inflammatories before the match started, and it took 45 minutes before they started to kick in," she said. "I was feeling a lot better in the second and the third set, but obviously maybe I had a bit of fatigue from yesterday's match when I finished really late.
"She was also playing very well in the first set, so maybe the combination of the two made the first set 6-1 to her," Bartoli added.
Just when she looked headed for a quick exit Bartoli's physical complaints faded away and she slowly began to take charge of the match against her less experienced opponent.
Bartoli earned and then surrendered an early second-set break but broke again for a 5-3 lead on her way to levelling the match.
She opened the third set with a break as Chan's game began to fray.
"I tried to really stay focused and positive and I'm glad I was able to turn it around," Bartoli said.
Chan held for 3-4 in a game that went to deuce six times, but she couldn't stop Bartoli's momentum as the French player held serve, then claimed the contest with a service break as Chan double-faulted to give her three match points then sent a forehand long on the first.
Bartoli, who emerged with the victory despite 14 double-faults and no aces, will be seeking her first title since she won in Osaka in October of 2011.
Cibulkova reached her first final since the clay court tournament in Barcelona in April.
The Slovak pocket rocket, who stands just 1.61 meters (5 feet, three inches), played a big match to impose her game on Petrova, who was attended by the trainer after losing the draining, 63-minute opening set.
She then stormed through the second set, wrapping up the victory in just over 90 minutes.
"I'm pretty sure that the tiebreak was the key to why I won the match," Cibulkova said. "After that, she went down a little bit."
Cibulkova recovered from an early break to force the first-set tiebreaker with a break in the 12th game.
Petrova raced to a 4-0 lead in the decider, but she was slowly pegged back by her persistent opponent.
"When she was up 4-0 I just said to myself, 'I don't want to give it up. I just want to make it as tough as I can for her,'" said the winner. "I fought for every ball."