Novak Djokovic put a firm stamp on his position as world number one with a stunning victory over Roger Federer in the ATP World Tour Finals. The Serb won 7-6 (8-6) 7-5 to add the season-ending title to his Australian Open victory and top ranking.
He needed two hours and 14 minutes to take two sets in a match of dramatic swings in momentum.
It is the second time Djokovic has won the ATP finale, following his triumph in Shanghai four years ago.
