Novak Djokovic has equalled Steffi Graf's record for most weeks as world number one after starting his 377th week at the top of the men's rankings.
On Monday, he moved level with Germany's Graf, who first rose to the top of the women's rankings in 1987.
Djokovic first became world number one in 2011 and like Graf, is a 22-time Grand Slam champion.
After first becoming world number one, Graf remained at the top of the rankings for 186 consecutive weeks, a women's record that was later tied by Serena Williams in 2016.
Djokovic's longest continuous run at the top was 122 weeks between July 2014 and November 2016.