Djokovic held off the No. 7-seeded Argentine del Potro 7-5, 6-3, while the Russian Davydenko needed to come from a set down to top the Frenchman Tsonga 6-7(6), 6-4 , 7-6(0).

Monday’s action will feature world No. 2 Roger Federer vs. Frenchman Gilles Simon, and Andy Murray vs. Andy Roddick.