NOVAK Djokovic paid tribute to the victims of the Paris terrorism attacks after beginning his ATP World Tour finals campaign with 6-1, 6-1 dismissal of Kei Nishikori. All the players wore black ribbons on their shirts as a mark of respect to the victims of Friday's atrocity, which saw 129 people killed at various locations across the French capital, and Djokovic led the o2 crowd in a burst of spontaneous applause for them after taking just over an hour to take care of the Japanese No 8 seed. "All my heart goes out to the families of the lost ones, it's really devastating to see those images and that footage," he said.

Djokovic also sent out a message to the rest of the field, after admitting he is playing some of his best tennis of the year. Considering the Serbian is in the throes of his finest ever year on the tour, winning 78 matches and losing just five times during 2015, that is quite a statement to make. Nishikori had previously won two of the pair's six meetings on tour, including a shock semi-final victory at last year's US Open, but he never got a look-in here.

"There's no question that I played maybe some of the best tennis I played this year," said Djokovic. "That's how it felt. On the other hand, Kei, he didn't perform at his best. But I think that's mostly because I was playing so well. I wasn't allowing him to perform at the level where he wanted to be."

This was a mature performance from Djokovic, who also spoke movingly on the subject of the Syrian refugee crisis, having seen first hand how many are passing through his native Serbia. He re-iterated that he could well not have been playing tennis by now, having thought about giving up the sport back in 2010.

"Many different factors have happened in order for me to be where I am at this stage," he said. "I'm 28 years old and there is a reason why I've managed to reach the peak of my physical, mental abilities at this stage of my life. I've had that great joy to win a first Grand Slam when I was 21 years old. Ever since then to this point, it's been seven years of a long process of learning, ups and downs, doubts, self-belief, some tough moments where I even considered of not playing tennis back in 2010. You go through these stages. Everybody does. It's just a normal, natural progress and process of development where I was fortunate to really have some great people who cared about me and who helped me to get to where I am today."