MEXICO CITY - South Africa's Louis Oosthuizen fired an eagle and five birdies in a seven-under-par 64 on Thursday to take the first-round lead in the WGC Mexico Championship.
The 2010 Open champion landed his 230-yard approach shot at the par-five 15th five feet from the pin and rolled in the putt for an eagle that gave him a lead he wouldn't relinquish.
"I'm very confident with my driver at the moment," Oosthuizen said. "I've got a nice little cut going and it's nice to be able to just aim left and swing away."
He was one stroke in front of England's Chris Paisley, India's Shubhankar Sharma and American Xander Schauffele, the US PGA Tour's 2017 Rookie of the year.
Paisley, 31, earned his first European Tour title at the BMW SA Open in January. Fifth place finishes at Abu Dhabi and Dubai saw him punch his ticket to his first elite World Golf Championships event at the Club de Golf Chapultepec.
Paisley opened with back-to-back birdies and added two more at the fifth and sixth, seizing a share of the lead on five-under with a birdie at the 10th, where he rolled in a 10-footer.
He drained a 40-foot birdie putt from the fringe at 14 and moved to seven-under with a birdie at 15 before giving a stroke back with his lone bogey of the day at 16.
"It's the biggest tournament I've played in by a long stretch," Paisley said. "To play as well as I did and shoot a good score against the world's best players and be right up there, Im just delighted."
"I didn't want to come here and just be happy to be part of it and just make up the numbers," he said. "I like the course, it kind of suits my strengths."
Schauffele had six birdies in his 65 while Sharma waited out a late lightning delay and birdied his final hole, the ninth, to join the group sharing second.
He also eagled the first, chipping in from 30 feet.
This week marks Sharma's first appearance in a WGC event. He has won twice on the European Tour this season and is out to improve from his current 75th in the world to a top 50 spot that would see him into the Masters.
It was a further stroke back to Spain's Rafael Cabrera Bello and Thailand's Kiradech Aphibarnrat on 66, with world number two Jon Rahm alone on four-under 67.
Defending champion Dustin Johnson emerged from a roller-coaster round with a two-under par 69.
The highlight was a near-ace at the 17th, his eighth hole of the day -- where his tee shot spun within inches of the cup.
Johnson finished with six birdies, two bogeys and a double-bogey six at the par-four 14th.