Roger Federer becomes oldest world no. 1 in tennis history

Twenty-time Grand Slam champion Roger Federer has become the oldest-ever men's singles world number one tennis player, at the age of 36. Federer achieved the feat by defeating Dutchman Robin Haase in the Rotterdam Open quarterfinals on Friday. Federer surpassed eight-time Grand Slam winner Andre Agassi, who was 33 years old when he became world number one in 2003.