MADRID - Rafael Nadal got through another young opponent and showed signs he was getting closer to his best form on clay as he defeated Alexei Popyrin 6-3, 6-3 to make it to the Madrid Open quarterfinals on Thursday.

Nadal overcame eight aces and saved five break points against the Australian. The five-time Madrid champion cruised past Spanish teenager Carlos Alcaraz in the second round on Wednesday.

“There is a lot of young, good players. (It's) something normal that is happening,” said Nadal, who at 34 is 13 years older than Popyrin. “And, yeah, I'm excited that at my age I am able to keep playing against all of them. They are good. They are talented. They have a great future. For me it's amazing to be where I am with my age competing with them still.”

Nadal struggled at times against the aggressive style of the 76th-ranked Popyrin but was able to stay in control for most of the match on the Magic Box centre court.

“I knew he was coming with confidence, he has this energy that the young players have,” Nadal said. “From what I could do, it was a good match, and I'm happy to make it to the quarterfinals again here.”

Nadal will next face fifth-seeded Alexander Zverev, who defeated Daniel Evans 6-3, 7-6 (3). The sixth-ranked German has won his last two matches against Nadal, though none were on clay.

Third-ranked Daniil Medvedev lost to Cristian Garin 6-4, 6-7 (2), 6-1. The Chilean broke serve twice in the third set to reach his second Masters 1000 quarterfinal. He will face eighth-seeded Matteo Berrettini, who defeated Federico Delbonis 7-6 (4), 6-4.

Earlier, U.S. Open champion Dominic Thiem reached the last eight by defeating Alex de Minaur 7-6 (7), 6-4. The third-seeded Austrian is playing in his first tournament since taking a few weeks off after a slow start to his year.

“There were some good, long rallies. I was many, many times out of breath,” Thiem said. “It was perfect for me to get back a little bit the match rhythm, to run down a lot of balls. As it's my first tournament, as it's my way back, a buildup for the next week, it was great for me.”

Thiem's opponent in the quarterfinals will be American John Isner, who used 29 aces - including two consecutive to clinch the deciding tiebreaker - to defeat sixth-seeded Andrey Rublev 7-6 (4), 3-6, 7-6 (4).

“To be honest, Andrey was the best player,” Isner said. “My serve kept me in the match. It's been like that a lot throughout my career.”

Fourth-seeded Stefanos Tsitsipas, who lost to Nadal in the Barcelona final, fell 7-6 (4), 6-4 to Norwegian Casper Rudd, who is coming off consecutive semifinal appearances in Munich and Monte Carlo.

“I'm feeling good, especially here in Europe on the clay. It was a part of the season last year that I was looking extremely much forward to and unluckily it was kind of taken away from all the players,” the 22nd-ranked Ruud said. ”This was one of the tournaments that we didn't get to play last year, so I'm just trying to enjoy the moment and take care of the chances that I get.“

Ruud's next opponent will be Alexander Bublik, who defeated Aslan Karatsev 6-4, 6-3 to reach his second Masters 1000 quarterfinal of the season.

In the women's final, top-ranked Ash Barty will face fifth-seeded Aryna Sabalenka, who defeated Anastasia Pavlyuchenkova 6-2, 6-3.

Barty cruised into the final with a 6-4, 6-3 win over wild-card entry Paula Badosa, the first Spanish woman to reach the semifinals in Madrid.

“I know it's been a big tournament for her, she's played an exceptional level of tennis,” Barty said. “She served particularly well, being able to control the court with her forehand. I think that was a challenge today. I was trying to neutralize that as best I could.”

Badosa had been the only opponent to defeat Barty since February. Barty has won 16 straight matches on clay and will be playing in her fourth final this year, having won the previous three.