World No 1 Novak Djokovic got the defence of his ATP World Tour Finals crown off to a winning start with a 6-1 6-1 victory over Marin Cilic in London.

The 27-year-old, who is undefeated indoors in 27 matches, looked completely at home in the O2, where he has triumphed in each of the last two years.

This was the perfect start for the Serb, who is aiming to become the first man since Ivan Lendl in 1987 to win this event three times in a row, and an ominous one for the other seven finalists.

The match represented a disappointing Tour Finals debut for US Open winner Cilic, who has now lost all 11 of the matches he has played against Djokovic.

Reflecting on the win, Djokovic said: "It's been a great, great match. I haven't played here for 12 months, it's great to be back. It was a great performance.

"Marin as a US Open winner has a lot of confidence, but I managed to neutralise his serve and get a lot of ball back in play and that was part of the tactic."

The only time Cilic looked comfortable in the match was in the opening game, which he won to love.

The Croatian lost the next eight games as Djokovic came to the fore, breaking for the first time in the third game to take a grip on the match he refused to relinquish.

Cilic has worked hard under coach Goran Ivanisevic to improve his serve but Djokovic was equal to it, producing a series of devastating passing shots to break twice more and take the first set in 27 minutes.

Djokovic charged into a 2-0 lead in the second set before Cilic was able to briefly halt the reigning champion’s momentum by taking the third on serve.

But this was only a brief interruption to Djokovic’s charge to victory, which he achieved with ease by taking the next four games to close out the win in under an hour.
(Sky Sports)