Alexander Zverev has prevented veteran Roger Federer from reaching 100 career titles by stopping the Swiss in the semi-finals at the ATP Finals.
The 21-year-old Zverev overcame the 20-time Grand Slam winner 7-5 7-6 (7-5) at London’s O2 Arena.
He will take on Novak Djokovic or Kevin Anderson, who play later on Saturday.
Zverev was booed at the end of the match after he had, rightly, stopped a point in the tie-break when a ballboy dropped a ball.
“I apologised to Roger at the net already, he said it is OK and it is in the rules,” the world number five said.
“I’m sorry this happened. I didn’t mean to upset anybody.”