France's Marion Bartoli shrugged off a stomach bug to reach the Indian Wells WTA tournament's semi-finals with a 6-4, 7-6 victory over former world number one Ana Ivanovic on Wednesday.
Bartoli, at 26 the oldest player left in the draw, won three consecutive games to claim an error-littered first set and ended the match by clinching the second set tiebreak 7-4 with an overhead smash into an open court.
The Frenchwoman, handed a place in the last eight when Belgian Kim Clijsters retired during the second set of their encounter the previous day with a painful shoulder, knelt down on the court and pumped both fists in celebration.
She then ran over to the players' box to kiss her father and coach Walter Bartoli, who introduced his daughter to the game at the age of six.
"I'm super-excited and so happy to be in the semi-finals at Indian Wells," said 15th seed Bartoli, who will meet Belgian Yanina Wickmayer in the last four.
Wickmayer, the 23rd seed, upset 10th-seeded Shahar Peer 6-3, 6-3 after breaking the Israeli's serve five times. It was her third victory over Peer in five meetings.
The other two quarter-finals, pitting top seed Caroline Wozniacki against eighth-seeded Victoria Azarenka of Belarus and then former world number one Maria Sharapova against China's Peng Shuai, were scheduled for Thursday.
Wednesday began on a low note for the ailing Bartoli who had been unable to eat anything for breakfast.
"I slept before my match because I was really feeling sick," she said.
"I went on court and at the beginning, the weather was not that hot, so it kind of helped me.
"But then it started to feel really hot and then in the end of the first set I was definitely not feeling very good," she added.
There were eight breaks of serve in a wildly fluctuating second set before Bartoli, renowned for her two-handed play on both sides, took control in the tiebreak.
"To be able to still win these kinds of matches against a player as good as Ana, it means a lot to me," she said with a smile after reaching her third WTA semi-final this year.
"The thing about Ana, sometimes she just plays too good. Even if you come up with some great points, she just fires back with some amazing shot. Sometimes she was breaking me to love and I was not even serving poorly," she added.
Asked how she managed to muster the energy to win the second set when clearly struggling on court, Bartoli replied: "I was taking a lot of time between the points, walking very slowly.
"I really took the bit of energy I still have in my body to try to save it. In a way, it helped me to relax but I knew I had to finish in two sets, because three would have been very difficult."
Ivanovic, champion here in 2008 and runner-up in 2009, had been aiming to reach her first WTA semi-final of the year.