World number one Novak Djokovic began his campaign for a record-equalling sixth ATP Finals title with straight sets win against Norway's Casper Ruud.

Djokovic triumphed 7-6, 6-2 in just over an hour and a half in Turin to go top of his group ahead of the match between Stefanos Tsitsipas and Andrey Rublev.

Djokovic fired 10 aces and 21 winners while Ruud managed nine aces and 26 winners and just 63 percent of his first serve points compared to Djokovic's 90 percent.

Ruud began brightly breaking Djokovic in the first game of the first set, the only time he would manage the feat against the Serbian. Djokovic's break of serve in the sixth game leveled it at 3-3 at the set headed into a tie-breaker which the top seed eventually won 7-6 (7-4).

Two breaks of serve in the first and fifth games of the second set gave Djokovic a 4-1 lead and he would go on to convert his second match point to claim the set 6-2 and seal victory.

Following the match, Djokovic was awarded the year-end ATP Tour No. 1 trophy as he finished top of the rankings for a record seventh time moving one clear of American legend Pete Sampras.

Should Djokovic claim the ATP Finals title, he will move level with Swiss star and fellow 20-time Grand Slam winner Roger Federer.

(With input from agencies)