PARIS: Novak Djokovic will on Monday set a new landmark of 311 weeks as world number one, surpassing Roger Federer whose hold on a record-equalling 20 Grand Slam titles is now firmly in the Serb's sights.

The 33-year-old Djokovic, already the winner of 18 majors, has time on his side with Federer turning 40 in August.

He is also a year younger than Rafael Nadal who also has 20 majors.

"Now that I've become the historic No.1, I'm relieved," said Djokovic after sweeping to a ninth Australian Open last month which guaranteed his extended stay at the top.

"Now, I'm going to be able to focus mainly on the Grand Slams."

Djokovic reclaimed the top ranking from Nadal in February 2020 and finished as year-end number one for the sixth time, tying the mark set by Pete Sampras.

He is currently in his fifth different spell atop the rankings.

Nadal, currently at number two, has been at the top for 'only' 209 weeks in total although the 13-time Roland Garros champion can boast being a top 10 ever-present since April 2005.

He will, however, lose his world number two spot to Daniil Medvedev a week on Monday.

Federer, who returns to action in Doha next week after more than a year out of action to recover from two knee surgeries, will slip out of the top five on Monday.

Djokovic made his top 100 debut in July 2005, just weeks after Nadal had won his first Roland Garros.

He was top 50 in June 2006, top 20 for the first time in October 2006 and top 10 by March 2007.

He first became world number one at the age of 24 on July 4, 2011, the day after winning Wimbledon for the first time, beating Nadal in the final.