NEW YORK (Kyodo) -- Kei Nishikori withstood a fightback from Italy's Salvatore Caruso on Tuesday to advance to the second round of the U.S. Open with a 6-1, 6-1, 5-7, 6-3 win.

       Playing his first match in three weeks due to a right shoulder injury, the world No. 56 from Japan took control early before the 113th-ranked Caruso tilted the momentum in the third set.

       The Italian broke Nishikori twice in the fourth set, but the former world No. 4 used his strong return game and net play to reassert control before closing out the match.

       "There were quite a few dangerous moments in the third and fourth sets, so it was a relief to wrap it up in four," said Nishikori, a U.S. Open finalist in 2014.

       "I'm glad I was able to play well in a difficult situation."

       The shoulder injury forced Nishikori to withdraw from the National Bank Open in Toronto last month after winning his first-round match.

       "I couldn't practice serving until recently," he said.

       Compatriot Yoshihito Nishioka lost his U.S. Open first-round match against Jack Sock of the United States 6-7, 6-2, 6-4, 6-2, while Nao Hibino bowed out of the women's draw in a 6-1, 6-4 defeat to France's Fiona Ferro.

       Font Size S M L Print