The Warrnambool export sat tied for 16^th, just four shots off the pace, after firing an opening round two-under par 68 at the St Louis-based Bellerive course.

Leishman, who is chasing his maiden major victory after two top-five finishes, had a shaky start, with a bogey on the second hole.

But he recovered to shoot three birdies in the next five to be at 33 after the opening nine. He carded one birdie and one bogey on the back nine.

The world number 18, who paid tribute to his late mate and fellow golfer Jarrod Lyle, was the second-best ranked Australian. Jason Day shot three-under for the opening round to be tied for fifth.

American Gary Woodland carded seven birdies to hold a one-shot lead at six-under.

His compatriot Rickie Fowler sat in second spot with South African Brandon Stone and American Zach Johnson tied for third at four-under.