Alcaraz, Tsitsipas advance in Madrid; Medvedev, Rublev lose

WATCH:Stefanos Tsitsipas defeats Bernabe Zapata Miralles in the 2023 Madrid Fourth Round

Carlos Alcaraz made sure he wouldn't be among the top seeds being upset at the Madrid Open on Tuesday, playing well from the start to secure his spot in the quarterfinals with a 6-1, 6-2 win over Alexander Zverev.

After both second-seeded Daniil Medvedev and fifth-seeded Andrey Rublev lost their fourth-round matches at the clay-court tournament, Alcaraz cruised past 13th-seeded Zverev to stay on track to defend his title at home.

Fourth-seeded Stefanos Tsitsipas also avoided an upset, defeating Bernabe Zapata Miralles 6-3, 6-1. In the women's draw, second-seeded Aryna Sabalenka reached the last four by rallying past Mayar Sherif in three sets.

The match between Alcaraz and Zverev was a rematch of last year's Madrid final, which Alcaraz also comfortably won against the former two-time champion in the Spanish capital.

"For me it's amazing to play the level that I played today," Alcaraz said. "I feel really good right now and this match gives me a lot of confidence."

Alcaraz didn't concede any break opportunities against Zverev and converted on four of the 10 break chances he had. The 19-year-old Spaniard ended with 21 winners and 12 unforced errors. Zverev had only nine winners and 22 unforced errors.

"This is not a normal result, Zverev is a great player and has great shots, it would be more normal to be a tighter match and I was prepared for it," the second-ranked Alcaraz said. "I played well. I kept attacking and didn't let him take control, especially on his serve. I played a complete match, that's why the result was like that."

Alcaraz, coming off the title in Barcelona, has won 18 straight matches in Spain.

Sabalenka reached the last four after trailing Sherif by a set and a break. Sabalenka came from behind to beat the Egyptian 2-6, 6-2, 6-1. The Australian Open champion reached her fifth semifinal in seven tournaments. She won Madrid in 2021.

The 59th-ranked Sherif was the first Egyptian to make it to the quarterfinals in a WTA 1000 event.

"It was crazy match. I think she played unbelievable tennis. It was really tough today," Sabalenka said. "I just couldn't adjust for her game, and I was really going crazy. I'm really happy that I was able to stop myself, to take a little breath and just like start everything from the beginning."

Sabalenka will next face ninth-seeded Maria Sakkari, who rallied to defeat Irina-Camelia Begu 6-7 (3), 6-4, 6-2.

Medvedev lost to 121st-ranked qualifier Aslan Karatsev, a fellow Russian, 7-6 (1), 6-4. It was Karatsev's first victory against a top-10 opponent since 2021.

Medvedev complained of the small dimensions of the Arantxa Sanchez Vicario court, saying he should have played on center court as the No. 2 seed.

Karatsev is a former No. 14 in the world and has won three tour titles, the last in Sydney last year. He was a semifinalist at the Australian Open in 2021.

"I'm feeling great," said Karatsev, who will next play against China's Zhang Zhizhen, who came from behind to defeat American Taylor Fritz in a thrilling 3-6, 7-6 (5), 7-6 (8) victory. Zhang saved three match points on his way to becoming the first Chinese player to reach the quarterfinals of an ATP Masters 1000.

Rublev lost to his doubles partner and also fellow Russian Karen Khachanov 7-6 (8), 6-4. Khachanov saved two set points in the tiebreaker in his first win against a top-10 opponent on clay since 2019.

The 12th-ranked Khachanov believed their tiebreaker was crucial after losing to Rublev in Monte Carlo three weeks ago, when Rublev went on to capture his first Masters 1000 title.

"It's always tricky to play against each other because, on one side, we know each other's games perfectly because we've been training together for so many years," Khachanov said. "At the same time, we know what to expect, but also of course a bit nervous to play against each other. We are good friends."

Khachanov, who improved to 19-0 after winning the first set in 2023, will face Alcaraz in the quarterfinals.

WATCH:Carlos Alcaraz defeats Alexander Zverev in the 2023 Madrid Open fourth round

Khachanov and Rublev made it to the doubles quarterfinals, where Jamie Murray and Michael Venus await.

Lucky loser Daniel Altmaier reached the quarterfinals by defeating Jaume Munar 6-3, 6-0.

Munar was upset with a call that put him down 3-0 in the final set. He challenged it and was irate when the ruling against him stood, saying: "I will destroy this machine. How is it possible? The mark is clear."

He walked to what appeared to be some tour officials near the court and argued with them about the challenge system, telling them "we are playing for 80,000 euros ($87,600) here."

Altmaier's next opponent will be Borna Coric, who defeated Alejandro Davidovich Fokina 6-7 (5), 6-3, 7-6 (5).