(Reuters) - American Scott Piercy and Marcus Fraser of Australia upstaged the biggest names in the game as they charged into a tie for the lead after the opening round of the WGC-Cadillac Championship in Miami on Thursday.
Piercy and Fraser fired matching six-under-par 66s on the daunting Blue Monster course at the Trump National Doral Resort, ending the day a stroke in front of five-times major winner Phil Mickelson, who birdied four of his last nine holes.
Englishman Danny Willett, Australian Adam Scott and Americans Jason Dufner and Charley Hoffman opened with 68s in the first of the year's four elite World Golf Championships events four while world number one Jordan Spieth carded a 69.
American Spieth attracted the biggest galleries of the day in a high-profile 'Big Three' grouping with second-ranked Australian Jason Day and third-ranked Northern Irishman Rory McIlroy.
Day offset four birdies with four bogeys to return a 72 while McIlroy spoilt an encouraging start to the week when he double-bogeyed his final hole, the par-three ninth, to shoot a 71.
(Reporting by Mark Lamport-Stokes in Los Angeles; Editing by Frank Pingue)