Zverev is through

ALEXANDER Zverev booked a semi-final against Roger Federer at the ATP Finals after knocking out John Isner.

The latest battle of big servers at the O2 ended in a 7-6 (7-5), 6-3 victory for 21-year-old German Zverev, ending Isner’s debut in the tournament.

Zverev’s win meant last night’s clash between Novak Djokovic and Marin Cilic was a dead rubber as world number one Djokovic is assured of top spot in the group and will face Kevin Anderson in the last four, while Cilic is already out.

“I’m unbelievably happy to be in the semi-finals in the last tournament of the year,” said Zverev. “John is such a tough opponent, so I’m just happy to be through.”