Zverev’s path to the top was supposed to go through Shanghai. It did not. The German reached the semi-finals there before falling to Alejandro Davidovich Fokina, banking 400 points and leaving the final piece of his No. 1 push for Austria.

The scenario in Vienna is now narrow but clear. If Zverev reaches the quarter-finals he is guaranteed to pass Sinner in the PIF ATP Rankings published on 2 November. Sinner has ended his 2026 season through injury and is defending every point he earned on the autumn swing, which has turned Vienna from a stop on the calendar into a title decider for the top spot.

A move to No. 1 would make the German only the second player from his country to lead the men’s rankings, after Boris Becker in 1991.

Alcaraz, back in Vienna for the first time in five years

Carlos Alcaraz is at the Wiener Stadthalle on a wild card, his first appearance at the tournament since 2021. That year, as an 18-year-old debutant, he reached the semi-finals and lost to the eventual champion. The eventual champion was Zverev.

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The Spaniard arrives sitting at No. 3 in the rankings, with a 33-5 record for the year and three titles already in the cabinet: the Australian Open, Doha and Tokyo. His place at the Nitto ATP Finals in Turin is secured.

Alcaraz starts against Karen Khachanov on Tuesday. The head-to-head reads 6-0 to the Spaniard, but Khachanov is a US Open semi-finalist this year and has the serve to make an indoor-hard first round uncomfortable.

Opposite halves, a potential final

The draw placed the top two seeds on opposite sides. Zverev opens against Spaniard Martin Landaluce, with Tommy Paul the seventh seed in his quarter. Alcaraz could face Daniil Medvedev deep in his own half if the seeds hold.

A meeting between Zverev and Alcaraz would therefore come only in Sunday’s final. If both reach it, the match would carry more weight than any ATP 500 final usually does: Vienna is the last 500-level event before the Finals, and the gap at the top of the rankings would be settled live on court.

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Monday opened with de Minaur and Berrettini through

The main draw started with the players chasing the final Turin places. Alex de Minaur, 10th in the Race, came back from a set and a break down to beat Tomas Machac 1-6, 6-4, 6-3 in just over two hours. It was his 18th ATP 500 win of the season, the most on tour this year.

“These conditions are quite heavy, and I felt like he could just unload on the ball and not really miss,” de Minaur told atptour.com after the match.

Earlier in the day Matteo Berrettini opened play on centre court with a 6-3, 6-4 win over Tomas Martin Etcheverry.

Zverev and Alcaraz are both scheduled for Tuesday’s day session, with their opening matches set for 10am local time.

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