March 1 (Reuters) - Former British Open champion Louis Oosthuizen, buoyed by a late eagle, held a one-shot lead after the first round of the WGC-Mexico Championship on Thursday while Jon Rahm and his fellow Spaniard Sergio Garcia lurked close behind.
Oosthuizen birdied three of his first five holes and then after two early birdies on the back nine carded an eagle at the par-five 15th en route to a flawless seven-under-par 64 at Club de Golf Chapultepec in Mexico City.
That left the South African world number 29 one shot clear of Briton Chris Paisley, American Xander Schauffele and Indian Shubhankar Sharma, who all shot 65s.
“I’m very confident with my driver at the moment. I’ve got a nice little cut going, and it’s nice to be able to just aim left and swing away,” said Oosthuizen.
World number two Rahm, playing in high-profile group with world number one Dustin Johnson and Justin Thomas, birdied his final hole, the par-four ninth, to sit alone in seventh place, three shots off the pace after a 67.
Masters champion Garcia was in a share of eighth with four other players after a three-under 68 that included seven birdies and four bogeys.
Thomas, fresh off his triumph at the Honda Classic, suffered a setback in his bid for back-to-back victories after mixing three bogeys with two birdies for a one-over 72.
Defending champion Johnson, who came within inches of a hole-in-one at the par-three 17th, was in a share of 13th after six birdies, two bogeys and a double-bogey. (Reporting by Frank Pingue in Toronto, editing by Nick Mulvenney)