Justin Rose shot 65 for a share of second place behind Germany's Alex Cejka after the first round of the Thailand Golf Championship.
England's US Open champion ended seven under alongside Thailand's Arnond Vongvanij to trail Cejka by one at the Amata Spring Country Club near Bangkok.
Defending champion Charl Schwartzel and Sergio Garcia both carded rounds of 68.
Sweden's world number three Henrik Stenson, and Americans Bubba Watson and American Rickie Fowler opened with 70s.
Rose, the world number four, said: "It was an early alarm call this morning at 4.30. Didn't enjoy that part but once I got out here to the golf course it was a perfect morning for golf, nice and cool to start with."