World No.1 Serena Williams clinched her 20th Grand Slam title by beating Czech 13th seed Lucie Safarova to claim the French Open here on Saturday.

American Serena needed two hours and one minute to win 6-3, 6-7 (2-7), 6-2 at Roland Garros.

Safarova was playing her first Grand Slam final. She put up a spirited fight despite losing the first set. She led by a break in the deciding third set but Williams utilised her vast experience and kept her composure to win the last six games.

Serena, 33, became the third player – male or female – to win 20 major singles titles.

Only Germany’s Steffi Graf on 22 has won more since the open era began in 1968, with Australia’s Margaret Court collecting 24 between 1960 and 1973.

It looked like it was going to be an easier day at the office for a while for Serena – after just over an hour on the court she found herself up a set and a double break at 6-3, 4-1, even going up 40-15 in that game – double game point for a seemingly unstoppable 6-3, 5-1 lead.

The match turned in a big way from there. Safarova dug out of that double game point and ended up winning five of the next seven games to push the second set to a tie-break, and after she raced through that tie-break, she raced out to an early 2-0 lead in the third set – Williams was in real danger.

But like she has done so many times in her illustrious career, she fought back to win six games in a row to edge Safarova.

An elated Williams spoke of her relief at winning a difficult match.

"It got really complicated today," Williams said.

"I was getting a little bit nervous, and Lucie was just playing great. She was a magnificent opponent. She was playing very aggressive and she had no fear."

"To win my 20th Grand Slam title at Roland Garros is very special for me because I haven’t always had the most success here. I want to thank all of the fans – it’s just a dream that I’ve won this title," she said.