Updated

Two-time champion Novak Djokovic was an easy second-round winner, while Jo-Wilfried Tsonga advanced via walkover at the $2.2 million China Open.

After shaking off the rust in his first match since losing to Andy Murray in last month's U.S. Open final, the world No. 1 Djokovic resembled his dominating form by routing helpless Argentine Carlos Berlocq 6-1, 6-3 on the hardcourts at the National Tennis Centre. The top-seeded Serbian star, who titled back-to-back here in 2009 and 2010, needed almost two hours to subdue German qualifier Michael Berrer in three sets on Tuesday.

The Australian Open champion and French and U.S. Open runner-up Djokovic's quarterfinal opponent will be veteran Austrian left-hander Jurgen Melzer. The former world No. 8 advanced with a 7-6 (11-9), 2-6, 6-1 upset of sixth-seeded Ukrainian Alexandr Dolgopolov, who fired 13 aces and managed to save 9-of-11 break points in a losing effort.

The third-seeded Tsonga was scheduled to face former world No. 3 Nikolay Davydenko on Thursday, but the Russian veteran pulled out of the draw Wednesday, citing a toe injury, as Tsonga received a walkover into the quarters.

One other second-round match saw German Florian Mayer rally past Romanian wild card Marius Copil 3-6, 6-3, 6-2.

The 2012 Beijing champion will earn $530,570.