LONDON, Jan. 14 (UPI) -- Novak Djokovic has a lock on the world's No. 1 men's tennis ranking as he competes in the first major tournament of 2013.
Djokovic, the two-time defending Australian Open champion, has a 2,655-point lead over No. 2-ranked Roger Federer with the third-ranked player -- Andy Murray -- nearly 5,000 points off the leader's pace.