The argument of who is the greatest tennis player of all time is settled according to former American tennis star Peter Fleming following Roger Federer's return to the top of the ATP men's singles ranking for the first time since October 2012.

The 36-year-old became the oldest world number one in tennis following his quarter-final victory over Robin Haase at the Rotterdam Open on Friday (16 February). He broke Andre Agassi's long standing record – the American was 33 when he reached the summit in 2003.

Federer's future in the game was questioned on more than one occasion during the period between 2013 and 2016 when he failed to win a single major title. He was then struck down by injury in 2016, which saw him sit out for almost six months, this again raised questions if he will ever get back to his best.

And get back to his best he did, with some even saying that he is probably playing better now than when he was 28 years old. Federer returned to action in 2017 after six months out with a knee injury and immediately claimed the 2017 Australian Open title in his first tournament back.

The Swiss tennis legend has since gone on to win seven more titles, which includes a record eighth Wimbledon title and defending his 2017 crown in Melbourne earlier this year. He marginally missed out on the world number one ranking to Rafael Nadal last year, but has ensured that he reclaimed his spot at the top after beating Haase to make it to the semi-final in Rotterdam.

Fleming has no doubt that Federer is now the greatest ever player to have played the game. Rod Laver is widely considered one of the greatest, but the Australian himself has handed the title of Greatest of All Time (GOAT) to the Swiss maestro.

"What a great champion," Fleming said following Federer's return to the top of the rankings, as quoted by the Express.

"Shame that perhaps the match tonight became a bit of an anti-climax. But it just goes to show how difficult it is to compete against this guy for an extended period of time. He just wears you down, mentally or physically.

"But as you say, what an incredible effort. To come back after all those injuries, to come back after countless heartbreaking defeats to become No 1 again at the age of 36 and a half, incredible," the American added.

"There once may have been an argument as to who's the greatest player of all time. He's quickly silencing any detractors."

Roger Federer
Roger Federer became the oldest world number one in tennis following his win over Haase at the Rotterdam Open on Friday (16 February) Getty