NEW YORK, Aug. 30 (Xinhua) -- Novak Djokovic, the U.S. Open's defending champion and No. 1 seed, breezed throught Denis Kudla of the United States 6-3, 6-4, 6-2 on Friday night into the fourth round for the 12th consecutive appearance at Flushing Meadows.
"I managed to play almost pain-free," he said as his left shoulder injury. "That's a big improvement."
Two days earlier he had complained about how much that shoulder hurt after repeatedly being visited by a trainer during his previous match.
Asked at his news conference whether he had taken a pain-killing injection, Djokovic said he didn't want to discuss any specifics.
"I did a lot of things in the last few days to be able to play," he said.
Djokovic skipped practice Thursday to rest the troublesome joint; he is a righty but uses his left arm for his two-fisted backhands and his serve tosses.
Next the Serb will play a match Sunday against three-time major champion Stan Wawrinka.
Heading into that, Djokovic has won 36 of his past 37 Grand Slam matches and four of the past major championships.
He is pursuing a fourth title at the U.S. Open and 17th major trophy overall.
