Oldest person ranked world tennis number one (male)
According to Official Guinness Records,
Roger Federer (Switzerland, b. 8 August 1981) was 36 years 195 days old when he returned to the top of the ATP world rankings on 19 February 2018. It had been an unprecedented five years 106 days since the 20-time Grand Slam winner last topped the rankings, and 14 years 17 days since he first reached the number one spot, on 2 February 2004. As of 19 February 2018, the Swiss ace had spent an unprecedented 303 weeks as the top-ranked male tennis player.33 years 133 days – age at which previous male record holder Andre Agassi spent the last of his 101 weeks as world number one, in September 2003. 35 years 224 days – age at which previous record holder (overall) Serena Williams spent the last of her 319 weeks as world number one, in May 2017. Most weeks as world number one (male): 303 – Roger Federer;286 – Pete Sampras;270 – Ivan Lendl. Rafael Nadal, who Federer replaced at the top of the rankings, had spent 167 weeks at number one as of 19 February 2018. Most consecutive weeks as world number one (male): 237 – Roger Federer (2004–07);160 – Jimmy Connors (1974–77);157 – Ivan Lendl (1985–88). On 16 February 2018, the 20-time Grand Slam winner had been confirmed as the new world number one after beating Robin Haase in the quarter-finals of the Rotterdam Open. He went on to win the title in Rotterdam, beating Grigor Dimitrov 6–2, 6–2 in the final, aged 36 years 194 days. Only 11 players in the open era (since 1968) have won an ATP title at the age of 36 of over. Pancho Gonzales and Ken Rosewall were both title-winners at the age of 43. After defeating Haase at the Rotterdam Open, Federer tweeted: "Apparently I'm the oldest tennis player with a #1 ranking. Somebody might have mentioned that to me already but I had a hard time hearing."