Serena Williams has borne her share of unexpected losses — some of her worst here at the French Open. But in a Grand Slam final? With a dominating lead? That would have been novel even for her.

Williams avoided that plot twist Saturday afternoon by finding another gear — as she almost always does. The top-ranked American survived a mid-match lapse and a third-set deficit to beat 13th-seeded Lucie Safarova of the Czech Republic, 6-3, 6-7 (2-7), 6-2, for her third French Open title and 20th major championship.

“It makes this trophy really special,” said Williams, who improved to 32-1 this year, including 12-0 in three-setters, and stretched her unbeaten streak in majors to 21 matches. “I really wanted it. I wanted to win so bad.”

In the completion of Friday’s suspended men’s semifinal, No. 1 Novak Djokovic survived a furious push from No. 3 Andy Murray, 6-3, 6-3, 5-7, 5-7, 6-1.

Williams continues to reel in history, even at her tennis-advanced age of 33.

Only two women have won more Grand Slam singles titles than the American: Open-era leader Steffi Graf with 22 and all-time record holder Margaret Smith Court with 24.

Williams is within realistic distance of both. She also remains on track for a true calendar year Grand Slam, last accomplished by Graf in 1988. The last player to get halfway there was Jennifer Capriati in 2001.

“It’s pretty awesome to have 20,” Williams said. “Obviously I would love to win a [calendar year] Grand Slam.”

Winning in Paris was difficult enough. Williams overcame a mid-tournament flu, nerves and five three-set matches — the most in any major title run of her career.

She described her last 48 hours as “a nightmare” and said Saturday she didn’t know whether she would be well enough to play the final.

“I think this might have been her most challenging one,” Fed Cup captain Mary Joe Fernandez said.

It will not go down as her prettiest.

In the final, she committed 42 unforced errors, dumped nine double faults and was warned by the chair umpire for an audible obscenity.

Williams hasn’t lost a Grand Slam final since losing to Samantha Stosur at the 2011 U.S. Open. A similar outcome seemed unlikely Saturday on Court Philippe Chatrier. For a set and a half, Williams pummeled Safarova with 120-mph serves serve and quick-strike returns, especially from the forehand side.

Though Safarova, 28, offered some resistance, Williams showed no effects from the illness that left her looking lethargic, at least between points, in Thursday’s semifinal comeback against Timea Bacsinszky.

But leading 6-3, 4-1 and 40-15, Williams uncharacteristically cracked. The game’s best server unloaded three double faults, including consecutive mistakes to drop serve for the first time in the match.

“I was just so angry at myself,” Williams said. “I pretty much gave the [set] away.”

Emboldened, Safarova — an explosive, late-blooming lefty — seized the moment.

She reeled off four straight games — breaking Williams two more times, including at 6-5 when Williams served for the match — and then outplayed her in the tiebreaker.

As the games ticked away, so did Williams’s composure.

She pleaded to the sky, screamed “C’mons” and viciously berated herself in expletive-laced tirades. Midway through the third set, umpire Emmanuel Joseph slapped her with a warning.

By then it was immaterial. The sport’s best big-match player had reasserted her power game, and after falling into a 2-0 hole she won the final six games of the match.

“I couldn’t find any weapon that could stop her,” said Safarova, who was competing in her maiden Grand Slam final.

After handcuffing Safarova with another winning return on match point, Williams stood for a long moment, unable to believe she had found her way through all the adversity. When it sunk in, she dropped her racket and lifted her arms in triumph.

At 20-4, Williams owns the second-best winning percentage (.833) in major finals in the post-1968 Open era (for players with a minimum of five finals played). Court was 11-1 (.917) but 24-5 in her entire career (.827), which is lower than Williams’s current mark.

All four of Williams’s defeats in Grand Slam finals were in straight sets.

“I kept thinking, ‘Gosh, this would be really ironic if she ends of losing one of the few matches she’s ahead in,’ ” said Fernandez, who also comments for ESPN.

With victories at last year’s U.S. Open and January’s Australian Open, Williams is three-quarters of the way to another four consecutive majors — a repeat of the so-called “Serena Slam” of 2002-03 when the American won titles in Paris, London, New York and Melbourne. Considering her big serve and present form, the five-time Wimbledon winner will be a heavy favorite to add another.

Since returning to Grand Slam play at 2011 Wimbledon following an 11-month absence caused by injury and illness, Williams has captured seven of 16 majors she has entered.

Even her coach, the Frenchman Patrick Mourataglou, said he was left marveling at what she had overcome during her two weeks in Paris.

“She impresses me and everybody all the time,” he said.

He said winning a calendar year Grand Slam and catching Graf at the U.S. Open would be “huge” but cautioned that much road lay ahead.

“We’re still far,” he said.

On the men’s side, Djokovic advanced to his third French Open final, where he will face Swiss No. 8 seed Stan Wawrinka, who defeated 14th-seeded Jo-Wilfried Tsonga in four sets Friday.

Djokovic, seeking his first title in Paris and a career Grand Slam, played a dominant fifth set in a contest halted Friday because of an oncoming storm with the players locked at 3-3 in the fourth set.

Murray was unable to hold off Djokovic after rallying to force a fifth set when play resumed.

Djokovic, an eight-time major winner who ran his unbeaten streak to 28, clinched the 4-hour 9-minute match with an ace. Saturday’s play took 61 minutes.

“I don’t think I have done too much wrong, even today in the fourth [set],” Djokovic said. “He just came up with some great shots, great points.”

Djokovic broke Murray in the second game of the fifth set with the help of three unforced errors. Murray was unable to sustain his level, and Djokovic broke him again in the sixth game.

Djokovic is 41-2 this season, including 11-1 in deciding sets.

“He regroups well during matches,” said Murray, who has dropped his last eight matches to Djokovic since the 2012 Wimbledon final. “He didn’t at the beginning of his career, and now it’s something that he does extremely well, physically and mentally.”

Djokovic, 28, will play a third consecutive day when he takes on 2014 Australian Open champion Wawrinka in Sunday’s final.

He leads their head-to-head 17-3 and has won their last five meetings on clay. Djokovic bageled Wawrinka in the fifth set of the Australian Open semifinals, their only meeting in 2015.