The German’s straight-sets victory in the round of 16 ensured that he will become world No. 1 when the new rankings are published on Monday, 2 November. Zverev will be the 30th player to reach the summit of the men’s rankings since their introduction in 1973.
The achievement also makes the 29-year-old the second German man to become world No. 1, following Boris Becker, who reached the position in 1991.
Zverev takes control in the opening set
Zverev started strongly against an opponent who arrived in Vienna in excellent form after winning the Brussels title the previous weekend.
The top seed secured an early break and maintained his advantage through the opening set. Griekspoor improved his serving as the match progressed, but Zverev remained composed and closed out the set 6–4 after approximately 40 minutes.
The Dutchman had entered the contest on a six-match winning streak, having also defeated Brandon Nakashima in the opening round in Vienna.
German holds firm to seal historic victory
The second set proved more competitive, with both players producing strong service games and limiting opportunities on return.
Zverev eventually created the decisive opening at 5–5, earning two break points. Although Griekspoor saved the first with a powerful serve, he could not prevent the German from converting the second.
Serving for the match, Zverev recovered from an unforced error and produced a volley before finishing with an ace to complete the 6–4, 7–5 victory.
The win confirmed his qualification for the quarter-finals and secured the ranking milestone he had pursued throughout his career.
Zverev set to succeed Jannik Sinner
Zverev will replace Italy’s Jannik Sinner at the top of the ATP rankings on 2 November, ending Sinner’s 95-week reign, according to Flashscore.
His rise follows a remarkable season that has included Grand Slam success at the French Open and US Open, alongside consistent performances across the ATP Tour.
Zverev’s achievement places him among an exclusive group of players to reach the highest position in men’s tennis. He will now look to maintain his momentum in Vienna as he prepares for the closing stages of the season.
Quarter-final challenge awaits
Zverev’s next opponent at the Erste Bank Open is Britain’s Arthur Fery, who defeated Italian Lorenzo Musetti to reach the quarter-finals.
The German will aim to continue his run in Vienna while celebrating a breakthrough that marks a new chapter in his career.
Match details
• Tournament: Erste Bank Open, Vienna
• Round: Round of 16
• Result: Alexander Zverev defeated Tallon Griekspoor 6–4, 7–5
• Date: Thursday, 29 October 2026
• Ranking milestone: Guaranteed to become world No. 1 on 2 November 2026