Portugal Colonial - After a long slog to the top, Zverev leaps to No. 1 ranking

The 29-year-old German won his first two Grand Slam titles this year. He was sure to finish the year as number one after Jannik Sinner, who won the season-ending ATP Finals last year, ended his season prematurely because of injury.

Zverev completed the job early, however, as he secured the points he needed by beating Dutchman Tallon Griekspoor on Thursday to book his spot in the quarter-finals at the Vienna Open.

"(It is) very special. To have the feeling to be on the top of the world is amazing," Zverev said.

"It is different than winning a tournament or a title, but it's such a special feeling to know that the No. 1 is going to be next to your name when the new rankings come out."

Zverev became the 30th man to hold the No. 1 spot since the rankings were first published in 1973. Only John Newcombe, who was aged 30 upon his ascension in 1974, was older when he first rose to the top.

Zverev was born in Hamburg but his mother and father had both played tennis to a high level in the old Soviet Union.

"For me, my family is everything and I owe them a lot for helping me to become the tennis player that I am today," Zverev has said.

He was tipped for stardom from his youth, but his path has been anything but smooth. He lives with diabetes and in 2022 suffered a career-threatening ankle injury at the French Open.

He also plays in the shadow of domestic violence allegations by two former partners, Olga Sharypova and Brenda Patea, which he has strenuously denied.

The ATP Tour investigated one claim and found insufficient evidence to punish Zverev.

The case involving Patea, the mother of his daughter, led to a 2023 penalty order and fine from a German court.

Zverev appealed and the two reached a settlement in June of 2024 -- hours before he was due to play in the French Open semi-finals.

- Highs and lows -

Zverev, who idolised Roger Federer growing up, made his first Grand Slam final in 2020 at the US Open, agonisingly losing in five sets to Dominic Thiem after being 2-0 up.

"That was exactly the time when I had real struggles with my serve and my second serve," he said of that match.

"I knew that my serve could break down at any moment. That's one difference that I do feel now, luckily for me."

His seemingly unstoppable rise was temporarily halted when he tore ankle ligaments while playing Rafael Nadal in the Roland Garros semis two years later and he underwent surgery.

Returning in January 2023, Zverev captured a 20th career title in Hamburg before having a fine 2024 season, in which he powered into the French Open final and surged to world number two, dispelling concerns that he was mentally frail.

"In the life of a professional athlete, you will have the highest highs and the lowest lows," said Zverev.

"Getting caught up in the lows is the biggest mistake that you can make.

"You shouldn't try to evaluate everything when times are tough, you should try to find ways to get better when you're on a high."

A third Grand Slam final defeat followed at the 2025 Australian Open, in straight sets to Sinner.

There were successes along the way, the most notable a gold medal at the Tokyo Olympics in 2021, where he stunned Novak Djokovic before taking down Karen Khachanov in the final.

But doubts about whether or not he would break his Grand Slam duck resurfaced as Sinner and Carlos Alcaraz dominated men's tennis by winning nine consecutive majors between them.

Zverev says he never lost faith that he could break through.

"I believed in it. I believed that it's possible," he told reporters after winning his second Grand Slam of the year in New York in September, adding with a laugh: "I think not many of you guys did."

J.Oliveira--PC