PARIS, France - Iga Swiatek's teenage dream continued at the French Open on Saturday.

The 18-year-old from Poland, who won the girls' doubles title in Paris a year ago and the Wimbledon girls' singles title, ousted Monica Puig in the third round, 0-6, 6-3, 6-3, to set up a clash against defending champion Simona Halep.

"It was pretty hard for me. I don't know what happened in the first set. Well, I know, but even though I tried to change something after a few games, I couldn't," Swiatek told reporters after the match.

"I just thought the second set would be different. We'll start from the beginning. I waited until the end of the first set to focuse more, to get my power...I had nothing to lose. Playing against Halep is one of my dreams."

Making her French Open main draw debut, Swiatek becomes the second player born in the 2000s to reach week two of a major - following American Amanda Anisimova's efforts at the Australian Open. 

She started her second-ever Grand Slam fortnight at age 17, but the newly-minted 18-year-old needed to battle back from a big deficit after celebrating her birthday on Friday.

The Rio Olympic gold medalist hammered twice as many winners to unforced errors in the opening six games, and a nervy Swiatek coughed up 15 unforced errors in under 30 minutes of play.

However, the World No.104, who lost just three games in a second-round upset of No.16 seed Wang Qiang gradually worked her way into the match to secure a victory in an hour and 48 minutes.

She finally broke the Puerto Rican for the first time in the sixth game of the second set, and kept her lead after she dug out of 0-40 in her next service game.

Swiatek never relinquished an early advantage she built in the decider, as she broke to love in the third game, and sealed a spot in the second week with a forehand winner on her third match point.

The teenager racked up 31 winners to 20 unforced errors, which included a 15-to-6 ratio in the middle set, served six aces and saved all five break points against her, over the second and third sets.