Roger Federer became the oldest number one singles player in tennis history after beating Robin Haase in the ABN AMRO World Tennis Tournament quarter-finals in Rotterdam on Friday.
The 36-year-old Swiss, who won his 20th grand slam last month by claiming a sixth Australian Open title , replaced Rafael Nadal at the top of the ATP rankings with a 4-6 6-1 6-1 victory over Dutchman Haase.
Federer has surpassed Andre Agassi as the oldest player to occupy the summit of the men's game - the American was 33 when he was last on top in September 2003.
His return to the top spot will be formally rubber-stamped when the men's tour
rankings are published on Monday morning.
Federer also beats the mark set by the record holder in the women's game,
Agassi's American compatriot Serena Williams, who was 35 when she was last number one in May last year.
Federer was last number one in October 2012, and first had the status in February 2004.
He took one hour and 19 minutes to win on Friday evening, responding in emphatic fashion after losing a first set that had seen Haase break in the ninth game.
* Federer holds the record of 302 weeks as world number one. American Pete Sampras managed 286.
* Federer, 36, is now the oldest player to reach the top of the rankings. American Andre Agassi did it aged 33 in 2003.
* Federer is the oldest man or woman to be number one. Serena Williams was 35 when she relinquished top spot in the women's rankings in May.
* By returning to number one for the first time since Nov 2012, Federer has set a new record for the longest gap between separate stints in the position.
* He also sets a new record for the longest time between first topping the rankings and the latest spell there. Rafael Nadal did hold that record after reclaiming top spot last August, having first scaled the summit in 2008.
* Federer's 237 continuous weeks at world number one from 2004 to 2008 is also a record.
* First time reached number one: 2004
* Age when first reached number one: 22
* Since Federer was number one in 2012, Novak Djokovic, Rafael Nadal and Andy Murray have held the top spot.
* Federer had a five-year grand slam drought, ending it by winning the 2017 Australian Open to reach 18 majors.
* In winning this year's Australian Open he took his tally to 20, and has won three of the last five slams.
* Federer has been year-end world number one five times, one behind the record of Sampras.
* Only seven other players who were in the top 100 when Federer first got to number one are still in there now: Nadal, Tomas Berdych, Richard Gasquet, Feliciano Lopez, David Ferrer, Ivo Karlovic and Mikhail Youzhny.
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