Lucie Safarova advanced to her first Grand Slam final with a 7-5, 7-5 win over former champion Ana Ivanovic at the French Open on Thursday.

The 13th-seeded Czech player, who upset defending champion Maria Sharapova in the fourth round, has not dropped a set in the tournament.

She will be up against either 19-time Grand Slam winner Serena Williams or 23rd-seeded Timea Bacsinszky in Saturday's final.

Safarova is the first Czech woman to make it to the final at the French Open since Hana Mandlikova in 1981.

"It's a dream come true, I cannot believe it" said Safarova, having now beaten two Top-10 players for the first time at the same Grand Slam.

Safarova trailed 4-1 and 5-2 in the first set, before finding her stride and reeling off the next five games. She faltered when serving for the match at 5-4 in the second, though, hitting three double faults — including one on match point — before getting broken.

"I started a little slowly but I tried to keep up the level and tried to play very aggressive because that was the only way to get a win," Safarova said.

Safarova certainly took risks, hitting 36 winners compared to 31 unforced errors.

She was broken in her first service game as she struggled with Ivanovic's deep balls early on. But she broke back in the ninth game with a powerful backhand return. Ivanovic then made some sloppy mistakes, including two double-faults as she dropped her serve for the second time, and Safarova converted her first set point.

The left-handed Safarova saved two break points early in the second set, and instead it was Ivanovic who dropped her serve. After Ivanovic leveled at 5-5, the change of momentum did not last. The Serb dropped her serve in the next game and Safarova kept a cool head to serve out the match.

Ill and sluggish, Serena Williams overcame a big deficit to reach the French Open final by beating 23rd-seeded Timea Bacsinszky of Switzerland 4-6, 6-3, 6-0 on Thursday.

With the temperature nearing 85 degrees (30 Celsius) on the hottest day of the tournament, Williams walked ever so slowly to changeovers, where even lowering herself to sit down seemed to be difficult. During those breaks, she pressed ice towels against her forehead and neck and guzzled water.

Her coach, Patrick Mouratoglou, acknowledged during a mid-match TV interview that the top-ranked Williams has been sick recently.

Trailing by a set and a break at 3-2 in the second after 66 minutes, Williams completely turned things around to claim the final 10 games.

Now one victory from her third French Open championship and 20th major title overall, Williams faces 13th-seeded Lucie Safarova of the Czech Republic in Saturday's final.

"I tried everything. I thought if I lose, I will lose with a fight," Williams told the Court Philippe Chatrier crowd in French afterward. "I tried, I tried. I found the energy. I don't know where, but I found it. And I won. I hope that on Saturday, I hope ..."

Cutting herself off, she stepped away from the microphone, bent over and began coughing. She offered a quick wave, then collected her things and left. Off the court, she got a hug from Mouratoglou, who then helped her down the stairs toward the locker room.

Next comes Williams' 24th Grand Slam final, and Safarova's first. The left-handed Safarova eliminated defending champion Maria Sharapova in the fourth round, then held on to defeat 2008 French Open champion Ana Ivanovic 7-5, 7-5 in the semifinals.

Williams won despite dropping the first set for the fourth time in six matches at Roland Garros. She'd never fashioned that many comebacks at a single Grand Slam tournament over her long, successful career.

When this one was over, finally over, Williams leaned forward and rested her head on her hands atop the handle of her upside-down racket.