Shanghai  - Jo-Wilfried Tsonga blamed clueless ball kids for his opening loss at the Masters Cup, with the petulant French player perhaps finding excuses for his own rookie mistakes on court.

A debutant at the year-end event, the hyper-fit 23-year-old who won the Paris title a week ago said he "lost energy" waiting for hardd-working ball kids to fetch him his towel frequently between points as he went down in Gold group play to Nikolay Davydenko in three sets.

"When I ask for my towel, my towel didn't come," lamented Tsgona, "When I ask for a ball, the ball didn't come. That's it."

Shanghai - Nikolay Davydenko had to overcome a late struggle from Jo-Wilfried Tsonga before defeating the Frenchman 6-7 (6-8), 6-4, 7-6 (7-0) to start with a tight victory at the Masters Cup on Sunday.

The Russian had to sweep a third-set tiebreaker after failing to serve out victory leading 5-3 in the third, scratching through in two hours, 43 minutes.

Novak Djokovic broke his duck at the year-end spectacular, winning his first career match at the event after three 2007 losses.

The Serb overpowered Argentine Juan Del Potro 7-5, 6-3 to take the early lead in the Gold group.

Shanghai - Novak Djokovic broke his duck at the Masters Cup, winning his first career match at the season wrap-up after three 2007 losses.

The Serb overpowered Argentine Juan Del Potro 7-5, 6-3 to take the early lead in the Gold group.

"I'm happy to win, that's for sure, I'm satisfied," said Australian Open champion Dokovic.

"I played really well from the start and felt good on the court. But then suddenly I just lost momentum and started serving really badly.

"He got back to the game. It was my fault, but I played well in the important moments. I'm happy to get through in straight sets."

Shanghai - Proud Roger Federer has pronounced himself massively dissatisfied with his current label of "second best" in tennis after losing the number one ranking last August to Rafael Nadal.