The German, who beat world number one Novak Djokovic in the semi-final, takes the Olympic title at the Ariake Tennis Park, beating Khachanov 6-3 6-1.
Alexander Zverev the man who beat a shell-shocked Novak Djokovic in the semi-final of the men's singles tennis event to progress to the final, has gone one better in claiming the Olympic gold medal. The German dropped to his knees after beating ROC's Karen Khachanov 6-3 6-1 in little more than 79 minutes at the Ariake Tennis Park.
The 24-year-old had already stunned the world number one who was aiming for a Golden Slam – all four singles Grand Slams, plus the Olympic Games, in one year – in the semi-final, winning 1-6 6-3 6-1.
"I feel sorry for Novak, but he's won 20 Grand Slams, 550 Masters series or whatever. You can't have everything," said Zverev of the Serb after the match.
Khachanov, a quarter-finalist at Wimbledon, leaves the court with an Olympic silver medal.