CARLSBAD, California, July 20 (Reuters) - Top seed Marion Bartoli survived a scare to beat Christina McHale 7-5, 4-6, 6-4 at the Carlsbad Open on Friday, taking a little under three hours to reach the semi-finals.
The Frenchwoman's two hour and 50 minute victory was the last of three marathon contests under the hot Californian sun.
Taiwanese qualifier Chan Yung-jan saved two match points to upset third seed Jelena Jankovic 6-7 7-6 7-5 in three hours and 13 minutes.
Fourth seed Nadia dodged a bullet, but only just, the Russian edging Varvara Lepchenko of the United States 6-4 2-6 7-6 in two hours and 14 minutes.
Second seed Dominika Cibulkova was the only player who made it back to the changing rooms in less than two hours after a 6-4 6-4 win over Poland's Urszula Radwanska.
Bartoli, who came through a three-setter in her opening match against Vania King, stepped up the pace of her hitting at the right moment, breaking McHale to win the match with a vicious forehand crosscourt.
"I just kept fighting," the Frenchwoman told reporters. "All the matches seem to be so long for everyone.
"Maybe it's the surface, but everyone seem to be playing for more than three hours. I just kept fighting and kept believing in myself to the end."
Former number one Jankovic, who has a 6-10 since late April and has not won a title in two and half years, was disappointed in her result.
After Chan took a medical time out to treat heat illness down 3-1 in the second set, Jankovic lost four straight games.
"I was thinking, she's tired. She cannot walk any more. She's dead because of the sun," Jankovic said. "Then I slowed down my arm.
"I didn't accelerate. I wasn't bending. I didn't make her work for anything."
Chan, who reached the top 50 five years ago, has struggled with her singles since then and came into the tournament ranked number 161 and had to qualify for the main draw.
However, the two-times grand slam doubles finalist has recommitted to her singles game.
"It feels very special for me because she was former number one," said the 22-year-old Chan, who will face Bartoli in the last four.
"Also I had the surgery the end of last year, and this is my best results since then. It could be one of the best matches in my career."
Slovakian Cibulkova and Petrova will face off in the other semifinal. (Editing by Alastair Himmer)