Big guns off to a shaky start

Arron Oberholser, Justin Rose, Paul Goydos and two-time champion Jose Maria Olazabal were the only other players under par, with more than half the field on the course.

Phil Mickelson got off to a rough start in defence of his title, hitting his second shot from the pine straw and his third from the sand en route to a bogey on the first hole. He was 1-over through four.

Other well-known players were in even deeper trouble. Ernie Els made a double bogey on the first hole and was 4-over through five.