PARIS, June 7 (Xinhua) -- World No. 1 Rafael Nadal saw off Argentina's Diego Schwartzman in a rain-postponed men's singles quarterfinals and will next face fifth-seeded Juan Martin Del Potro at the 2018 French Open on Thursday.

Nadal lost the opening set 6-4, and went on to trail by 2-3 in the second on Wednesday when the match was spoiled by rain. Nadal won three games in a row after returning to court, but the match was stopped again in the ninth game.

The "King of Clay" regrouped himself on Thursday and wrapped up the match at 6-3, 6-2, 6-2.

"The stop yesterday helps, because it was in a tough moment of my match," admitted the Spniard, who made his 11th semifinal appearance at Roland Garros.

"He was playing great, and I was playing too defensive. I felt that I was playing a little bit under more stress than usual, and he was able to take control of the point too many times.

"Today I played more aggressive. I continued the level of intensity that I played after the first stop, and changed the match," he added.

"The rain was not a help to me," echoed Schwartzman.

"But it's always tough against Rafa (Rafael Nadal). Yesterday I was doing many winners, not many unforced errors. He was not playing his best tennis. Maybe the day when you can beat Rafa was yesterday.

"Today he started playing totally different, aggressive, doing winners, no mistakes. The match changed a lot," he said.

Nadal became the third man in the Open Era to reach 11 semifinals at a single Grand Slam tournament.

Del Potro will be his opponent on Friday after eliminating No. 3 seed Marin Cilic 7-6 (5), 5-7, 6-3, 7-5 to make into the semifinals for the first time since 2009.

"Because of the way he is, his fitness and the way he plays, he's the king of the tournament," Del Potro commented on Nadal.

"It's always a pleasure playing him in a Grand Slam. These are unique moments, and many players would like to have this opportunity. We have to enjoy the moment, and I will try to enjoy it tomorrow," the Argentine added.

The other semifinal will be played between No. 7 seed Dominic Thiem and Italian underdog Marco Cecchinato.