Stanislas Wawrinka has claimed that he is "happy" to progress from the first round of the US Open, but admits that his performance was inconsistent.
The two-time Grand Slam champion was tested, but came through a 7-5 6-4 7-6(6) victory over Albert Ramos-Vinolas.
"[I was] a little bit up and down," allsports.com quotes Wawrinka as saying. "In general it was a good match. It's always tough to play, never easy, especially first round.
"You need to get through those matches. I'm happy to get through in three sets. I think my level is there. Physically I feel good. I'm ready for the rest."
Wawrinka will take on Korea's Chung Hyeon in the second round.
