Alexander Zverev off the mark with a win against Marin Cilic

Alexander Zverev celebrates

Alexander Zverev overcame a sluggish start to beat Marin Cilic in his opening round-robin match at the 2018 ATP Finals.

The world No 5 found himself 3-0 down in the first set, but eventually found his rhythm and secured a 7-6 (7-5), 7-6 (7-1) win over former US Open winner Cilic in just over two hours.

Zverev broke back in game nine of the opening set and, after squandering a couple of set points in the tie-breaker, he eventually took the set in one hour and five minutes.

Cilic again had the initial advantage in the second set as he broke in game seven, but the German hit back in the very next game to draw level and then dominated the tie-breaker.

World No 1 Novak Djokovic will take on John Isner in the second match in the Guga Kuerten Group in the evening session at the O2 Arena in London.

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