Alexander Zverev has the opportunity to achieve the world number one ranking for the first time in his career.
The German superstar, who has won two Grand Slam titles this year, is guaranteed to end the 2026 season in the top spot.
Zverev will claim the world number one ranking for the first time in his career if he advances to the Vienna Open quarter-finals.
The German opened his Vienna Open campaign on Tuesday, beating Martin Landaluce in a close three-set contest. As a result, Zverev needs to win just one more match to be crowned as the world number one.
With Zverev’s historic achievement fast approaching, let’s take a look back at the player who became the first official world number one in 1973.
Ilie Nastase became the first official world number one in 1973
Ilie Nastase, a seven-time Grand Slam champion across singles, doubles and mixed doubles, assumed the world number one ranking in singles on August 23, 1973.
How long do you think Alexander Zverev keeps the number one ranking?
He is now guaranteed to be year end number one after Carlos Alcaraz’s shock loss in Shanghai…
Nastase rose to the pinnacle of men’s tennis following an exceptional 12 months on the professional circuit, during which he had captured Grand Slam titles at the 1972 US Open and 1973 French Open.
Nastase also won the 1972 Tour Finals, successfully defending his title from 1971.
The Romanian star held the position for 40 weeks before surrendering the top spot to seven-time major singles champion John Newcombe.
With 40 weeks to his name, Nastase has spent the 17th-longest time period as the world number one among all players since 1973.
A further 27 players have achieved the world number one ranking since Newcombe.
Alexander Zverev will become the 30th player to achieve world number one status when he claims the top position later this year.
| Player | Weeks as world number one |
| Novak Djokovic | 428 |
| Roger Federer | 310 |
| Pete Sampras | 286 |
| Ivan Lendl | 270 |
| Jimmy Connors | 268 |
| Rafael Nadal | 209 |
| John McEnroe | 170 |
| Björn Borg | 109 |
| Andre Agassi | 101 |
| Jannik Sinner | 95 |
| Lleyton Hewitt | 80 |
| Stefan Edberg | 72 |
| Carlos Alcaraz | 66 |
| Jim Courier | 58 |
| Gustavo Kuerten | 43 |
| Andy Murray | 41 |
| Ilie Năstase | 40 |
| Mats Wilander | 20 |
| Daniil Medvedev | 16 |
| Andy Roddick | 13 |
| Boris Becker | 12 |
| Marat Safin | 9 |
| John Newcombe | 8 |
| Thomas Muster | 6 |
| Carlos Moyá | 2 |
| Patrick Rafter | 1 |
| Alexander Zverev | 0 [guaranteed to become world number one] |
If Zverev achieves the top ranking in Vienna, he is guaranteed to hold the top spot for at least nine weeks.


