Alexander Zverev will officially become the world number one on Monday after reaching the quarterfinals of the Vienna Open.

Zverev has enjoyed a stellar year on the ATP Tour, clinching his first two Grand Slam titles at Roland Garros and the US Open, as well as reaching the Wimbledon final. Having recently confirmed year-end number one status, the German’s most recent victory over Tallon Griekspoor in Vienna means he will rise above Jannik Sinner to the top spot when the rankings are updated next week.

Zverev is the first German number one since Boris Becker in 1991, and the first across men’s and women’s tennis since Angelique Kerber in 2017.

Alexander Zverev reacts after becoming world number one

Speaking in his on-court interview after beating Griekspoor, Zverev said: “To kind of have the feeling to be on the top of the world is amazing. You know, it’s different than winning a tournament, winning a title, but it’s such a special feeling to know that the number one is going to be next to your name when the new rankings come out. So I’m super happy and super thrilled.

“I mean, I was super focused, super motivated, you know, for multiple reasons,” said Zverev about his pre-match thoughts. “But of course, number one was definitely a big subject. And I think I played a very good match and I’m very happy about that.”

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Zverev came close to becoming the world number one four years ago, but sustained a season-ending ankle injury during his 2022 Roland Garros semifinal match with Rafael Nadal, which ultimately derailed his pursuit of the feat.

“I had to wait,” said the 29-year-old. “But sometimes you’ve got to wait for the best things in life. So it is how it is. I’m super happy, super thrilled. This year, I mean, I have no words for this year. Again, I’m just thankful. I’m happy and all of the above.”

Zverev has risen above both Sinner and Carlos Alcaraz in the rankings this year despite not beating either of them in 2026. He lost to Alcaraz in their sole meeting of the season at the Australian Open and has fallen to Sinner five consecutive times.

It is likely Zverev will hold onto the world number one spot until Roland Garros, given how many points Sinner has to defend until then. Alcaraz is currently over 4,000 ATP points behind Zverev in the rankings due to his wrist injury that kept him sidelined for four months.

Zverev will now continue his Vienna Open campaign, where he is bidding to win his third title of the season. In the quarterfinals of the ATP 500 tournament he will take on Arthur Fery, whom he beat in the semifinals of Wimbledon.