Third seed, Alexander Zverev beat Marin Cilic 4-6, 6-3, 6-4 in Sunday’s second round-robin match in the Boris Becker Group.
The 20-year-old German rallied from a break down in the deciding set to overcome Cilic after 2hrs 5mins. The win moves him to the top of the group alongside Roger Federer.
“It is different walking on here than any other stadium. The crowd, the atmosphere is amazing,” Zverev said.
“There were a lot of nerves involved in my first match. Obviously I’m happy that’s behind me. I’m happy that I won.”
Zverev, bidding to become the first German to finish the year in the world’s top three since Boris Becker in 1994, will face a mouthwatering clash with Federer on Tuesday.
The action from London continues on Monday with action shifting to the Pete Sampras Group as Grigor Dimitrov takes on Dominic Thiem and World No. 1 Rafael Nadal begins his quest for a maiden Nitto ATP Finals title against David Goffin.