Djokovic, Davydenko take Masters openers

SHANGHAI, Nov. 9 (UPI) -- Serbian Novak Djokovic and Russian Nikolay Davydenko won their opening matches Sunday in the eight-player Tennis Masters Cup in Shanghai.

Djokovic, seeded No. 2, was a 7-5, 6-3 victor over Juan Martin del Potro of Argentina and Davydenko rallied to beat Frenchman Jo-Wilfried Tsonga 6-7 (6-8), 6-4, 7-6 (7-0).

The Masters Cup is a round-robin event with two four-player groups.

Gold Group openers were played Sunday and the Red Group begins play Monday with two-time defending champion and top-seed Roger Federer meeting France's Gilles Simon and Britain's Andy Murray going against American Andy Roddick.

Federer has won the 26 of 29 matches in the Masters Cup over the years.

World No. 1 Rafael Nadal bypassed the cup because of a knee injury.