Alexander Zverev’s serve saves the day in Australian Open thriller over Learner Tien

Alexander Zverev relied on his powerful serve to bail him out of trouble against Learner Tien, winning a tightly contested Australian Open quarterfinal on Rod Laver Arena.

The No. 3 seed fired 24 aces and just one double fault across four sets, saving all three break points he faced. His lone double fault came at the very end of the match, after he had surged to a 6-0 lead in the fourth-set tiebreak. Zverev quickly erased it with an ace to seal a 6-3, 6-7 (5), 6-1, 7-6 (3) victory in three hours and 11 minutes.

Afterward, Zverev had high praise for Tien, the rising 20-year-old American who added 1989 Roland Garros champion Michael Chang to his coaching team alongside Erik Kortland in August 2025.

“What impressed me the most is—and I talked to my team afterwards—I felt like I didn't have a spot on the court where I could just hit the ball and I felt like I was out of danger,” Zverev said in his post-match press conference.

“Doesn't matter what speed, doesn't matter the height. I felt like if I was hitting fast but in his racquet, he was using my speed to redirect the ball. If I was hitting a bit slower, he was taking the ball early, being aggressive himself," he explained.

“I felt like there was not really a spot on the court where you could just put the ball there and restart the rally, which was quite impressive. It wasn't that case last year, so he has improved a lot in that regard.

“Also got to give credit to Michael Chang, I think what he is doing with him is phenomenal.”

The German is now through to the Australian Open semifinals for the fourth time in his career.

He will face the winner of No. 1 seed Carlos Alcaraz and No. 6 seed Alex de Minaur in the semifinals.

Zverev has been tested throughout the fortnight, dropping at least one set in four of his five matches. He lost the opening set to Gabriel Diallo and the second set to both Alexandre Muller and No. 26 seed Cameron Norrie. The exception came in the fourth round, when he delivered a statement straight-sets win over No. 18 seed Francisco Cerundolo.

A three-time Grand Slam runner-up — at the 2020 US Open, 2024 Roland Garros and the 2025 Australian Open — Zverev said he was pleased to be through the early rounds as he continues his pursuit of a first major title.

“I feel like maybe top players feel the most pressure in the beginning, you know, not have an early exit,” Zverev told reporters in Melbourne.

“Now, whoever I'm going to play in the semis, Carlos or Alex, they're great players. You just are looking forward to a fantastic match...

“Of course, in my case, yeah, I'm still chasing that desired Slam. Of course, I still want to achieve that, but I also want to enjoy my tennis. Right now I'm doing that, and that's the most important thing for me.”