Alexander Zverev's run to the Vienna last eight puts him on course to snatch the world number one ranking from Jannik Sinner.
Alexander Zverev is closing in on the summit of men's tennis. His progress to the quarter-finals in Vienna means he is poised to replace Jannik Sinner as world number one at the earliest opportunity.
For the German, it is the kind of moment he has chased for years. Zverev has long been a fixture among the elite, a big-serving, big-hitting presence at the sport's biggest events. The top ranking is the one prize that has stayed just out of reach, and now it is within touching distance.
Sinner has set the standard at the top of the rankings, so any changing of the guard is significant. A switch at the summit would reshape the narrative heading into the closing stretch of the season, when the indoor hard-court swing puts a premium on consistency, fitness and nerve.
First Zverev has to finish the job in Vienna. The quarter-final is the next hurdle, and the German will know that the best way to make the ranking change official is to keep winning. The race for number one is on, and the next few days could decide how it ends.

