Oct 30 - Alexander Zverev ensured he would overtake Jannik Sinner in the rankings and become world number one for the first time next week with a 6-4 7-5 victory over Tallon Griekspoor in the last 16 of the Vienna Open on Thursday.

The 29-year-old, who has enjoyed a stellar season capped by titles at the French and US Opens, will become Germany's second men's number one after Boris Becker in 1991 when the new rankings are published on Monday.

Zverev's victory, which was sealed with an ace, was followed by a ceremony on court when he was joined by his team and Thomas Muster, the only Austrian to have topped the rankings, to mark the feat.

"[It is] very special. To have the feeling to be on the top of the world is amazing," said Zverev, who will be the 30th man to top the rankings since they were introduced in 1973.

"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."

Zverev would be the first to admit that injuries to Sinner and Carlos Alcaraz, who between them won every Grand Slam title in the 2024 and 2025 seasons, had eased his ascent to the top of the rankings.

Sinner decided to end his season in early October to recover from a knee injury but world number three Alcaraz was in action in Vienna earlier on Thursday and saved four set points to beat Nikoloz Basilashvili 6-1 7-6(11).

Zverev came close to taking the number one ranking in 2022 at the French Open but tore ankle ligaments in his semi-final against Rafa Nadal and missed the rest of the season.

"I had to wait, but sometimes you've got to wait for the best things in life," Zverev added. "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." REUTERS