New Delhi, April 1 (IANS): Serbian great Novak Djokovic, who began his 419th week in numero uno position, will break Swiss legend Roger Federer's record as the oldest No. 1 in ATP rankings history by the end of this week at 36 years and 321 days old.

In February last year, Djokovic surpassed Stefanie Graf’s tally of 377 weeks to claim the record for the most weeks by a men’s or women’s tennis player as World No. 1.

Djokovic first became World No. 1 on 4 July 2011 at the age of 24. In contrast, both of Djokovic’s great 'Big 3' rivals, Federer and Rafael Nadal, reached No. 1 for the first time aged 22, according to ATP stats.

Nearly 13 years after becoming World No. 1 for the first time, Djokovic has spent a large percentage of his time atop tennis summit. Monday signalled the start of his record-extending 419th week as World No. 1, meaning he is now 109 weeks clear of second-placed Federer (310 weeks).

Since he turned 30 on May 22, 2017, the Serbian has won 31 tour-level titles, including 12 of his 24 Grand Slams, 10 of his 40 ATP Masters 1000 crowns, and two of his seven Nitto ATP Finals trophies.