Alexander Zverev got off to a winning start in the ATP World Tour Finals with a 7-6(5) 7-6 (1) victory over Marin Cilic at the O2 in London.
Zverev was 0-4 down in the opening set as Cilic forced errors - but the Croat was unable to serve out the set at 5-3. Instead, he produced mistakes on his backhand and double-faulted, allowing the 21-year-old to regain a foothold.
Cilic again moved ahead in the second set after some wayward groundstrokes, but Zverev made a resurgence. Although the 30-year-old saved one match point with the score at 4-5, he could not hold off Zverev in the second tie-break.
It was an impressive second tie-break from the younger man as well, which he concluded with a backhand down the line and an unreturnable serve.