SHANGHAI, CHINA - NOVEMBER 16: A general view as Novak Djokovic of Serbia serves to Nikolay Davydenko of Russia during the finals of the Tennis Masters Cup at Qi Zhong Stadium November 16...

...the wi Novak Djokovic of Serbia holds up the winner's trophy following his victory over Nikolay Davydenko of Russia in the men's singles final at the ATP Masters Cup tennis tournament in...

SHANGHAI, CHINA - NOVEMBER 16: Novak Djokovic of Serbia celebrates match point and victory against Nikolay Davydenko of Russia in the Tennis Masters Cup held at Qin Zhong Stadium on November 16, 2008...

SHANGHAI, CHINA - NOVEMBER 16: (CHINA OUT) Novak Djokovic of Serbia reacts against Nikolay Davydenko of Russia at the men's singles final match in the Tennis Masters Cup held at...

SHANGHAI, CHINA - NOVEMBER 16: (CHINA OUT) Nikolay Davydenko of Russia hits a return against Novak Djokovic of Serbia in the men's singles final...

...Djokovic won 7-5, 6-3. AFP PHOTO (Photo credit should read AFP/AFP/Getty Images) Nikolay Davydenko of Russia celebrates winning match point against Andy Murray of Britain in their men's singles...

SHANGHAI, CHINA - NOVEMBER 15: Nikolay Davydenko of Russia returns a shot during his semi-final match against Andy Murray of Great Britain...

SHANGHAI, CHINA - NOVEMBER 13: (CHINA OUT) Nikolay Davydenko of Russia returns a shot during his round robin match against Juan Martin Del Potro of...

Nikolay Davydenko of Russia competes against Novak Djokovic of Serbia in a singles match of the ATP Tennis...

SHANGHAI, CHINA - NOVEMBER 09: Jo-Wilfried Tsonga of France reacts during his round robin match against Nikolay Davydenko of Russia in the Tennis Masters Cup held at Qi Zhong Stadium on November 9, 2008...

Spain's Rafael Nadal returns a shot to his Russian opponent Nikolay Davydenko during their ATP Paris Indoor Masters tounament quarter final tennis match on October 31, 2008 at...

...during a break of his ATP Paris Indoor Masters tounament quarter final tennis match against Russian Nikolay Davydenko (L) on October 31, 2008 at the Palais Omnisport de Paris-Bercy in Paris

PARIS - NOVEMBER 01: David Nalbandian of Argentina plays a backhand during his semi-final match against Nikolay Davydenko of Russia during the ATP Masters Series at the Palais Omnisports De Paris-Bercy on November...

...Nalbandi Argentina's tennis player David Nalbandian gestures after losing a point to Russia's player Nikolay Davydenko during their Davis Cup 2008 World Group semifinal match at Parque Roca stadium, in Buenos Aires...

Nikolay Davydenko of Russia returns the ball to Dmitry Tursunov of Russia during their match at the U...