PARIS (AP) — For one full set, Maria Sharapova was about as bad as can be.

The French Open’s defending champion could not direct the ball where she wanted at the start of her quarterfinal against Serbia’s Jelena Jankovic. Point after point ended with a mistake by Sharapova — long, wide, into the net, 20 unforced errors in all.

It added up to only the sixth time in 626 career matches that Sharapova dropped a first set at love. She lost all of those others, never even forcing a third set. Sharapova did not go quietly Wednesday, though, turning up the level of her shot-making and the volume of her “Come on!” shouts on the way to beating the 18th-seeded Jankovic 0-6, 6-4, 6-3.

“I wanted to put that chapter behind me,” the second-seeded Sharapova said. “No matter how many errors I made or how disappointed I was with the way I started the match, I knew that I still could try to create chances out there; obviously taking them is another question. But I knew that I was capable of doing much better.”

Jankovic didn’t so much earn her early lead as accept it: Of the 27 points she won in that first set, only two came via her winners.

Down the stretch, Jankovic faded, losing the final four games. She was wearing beige strips of tape on her right shoulder and both thighs and said playing singles, women’s doubles and mixed doubles these two weeks caught up with her.

“I needed a bit more gas in my tank to finish this match off,” she acknowledged.

In Thursday’s semifinals, Sharapova will face No. 3 Victoria Azarenka of Belarus, the two-time Australian Open champion, who eliminated her friend and former doubles partner, No. 12 Maria Kirilenko of Russia, 7-6 (3), 6-2 to reach the semifinals at the fourth major tournament in a row.

Azarenka, who is 7-5 against Sharapova, summed up their latest matchup of power-based games this way: “Definitely going to be exciting and interesting.”

The other women’s semifinal is No. 1 Serena Williams, a 15-time Grand Slam champion, against No. 5 Sara Errani of Italy. They won their quarterfinals Tuesday.

It’s the first French Open semifinal for Williams since 2003, the year after she won her only title in Paris. Errani, who is 0-5 against Williams, was the runner-up to Sharapova 12 months ago.

“I never expected to get to the semifinals this year after making last year’s final. There was a lot of pressure this year and I’m happy that I was able to handle it,” Errani said. “We’ll see how the semifinal goes.”

Sharapova’s 2012 French Open title completed a career Grand Slam, adding to championships at Wimbledon in 2004, the U.S. Open in 2006 and the Australian Open in 2008.

For someone who used to mock her own inability to move well on red clay, Sharapova sure is taking to the slow surface nowadays: She’s won 12 consecutive matches at Roland Garros, where her 42-9 career record leads active women.

Azarenka has never been as successful on clay as faster grass or hard courts, and Thursday’s match will be her first French Open semifinal.

But she’s getting more and more comfortable on what some players call “dirt.”

Asked by a reporter to describe her “relationship” with clay, Azarenka joked: “I still don’t have any ring on my finger. But I feel like, you know, we made a step forward. We are moving in together.”

Against 2008 U.S. Open runner-up Jankovic, Sharapova needed 35 minutes to win a single game.

In the meantime, nearly every point Jankovic claimed was raucously celebrated by a group of four fans sitting behind her brother (who is also her coach). At a changeover, Jankovic looked up at them with a wide smile as they sang her first name and waved a Serbian flag.

But eventually, Jankovic began missing more — and Sharapova began finding the range. A forehand winner helped set up a break point for Sharapova in the second set’s first game, and Jankovic handed it over with a double-fault.

That was part of a run in which Sharapova won seven of eight points to go ahead 2-0.

“Really important. You know, at least give her something to think about,” Sharapova said. “She was a bit in cruise control for a long period of time.”

At 3-all in the third, a pair of Jankovic backhands into the net and one perfect forehand passing shot by Sharapova led to the set’s first break point. Sharapova capitalized with a well-timed return of a 107 mph serve, forcing yet another backhand error.

The match was nearly two hours old, and Sharapova finally grabbed her first lead.

“It was certainly nice to change things around,” Sharapova said, “because I wasn’t doing much in the first six games.”