Roger Federer's record run as world No.1 to end, will skip French Open

The 36-year-old, who became the oldest man to top the rankings in February, also revealed plans to skip the clay-court season following his shock 3-6 6-3 7-6 (7-4) loss to world number 175 Thanasi Kokkinakis.

Last year, the same schedule saw him miss the French Open to focus on Wimbledon – a title he ultimately cruised to without dropping a set.

"I deserve it after this match. I feel so bad," Federer said about losing his No.1 status.

It was Federer’s second defeat in six days, with the Swiss succumbing to Juan Martin del Potro in the Indian Wells final last weekend.

He was expected to play the European clay-court season and challenge for the French Open – a tournament that appeared wide open with Roland Garros specialist Nadal still struggling with injury.

But the 20-time Grand Slam champion announced after his Miami exit that would not happen, saying "I decided not to play".

Strangely, Federer’s loss promotes Nadal to the top of the ATP rankings, despite the Spaniard last appearing at the Australian Open in January.

Nadal retired hurt in his quarter-final with Marin Cilic in Melbourne and could quickly relinquish his No.1 status back to Federer – who has no points to defend on clay – unless he returns to the court soon.

Meanwhile, Federer is likely to return at the Stuttgart Open on grass in June.