Bryson DeChambeau registered six birdies in a seven-hole stretch Friday and charged to the lead at the midway point of the World Golf Championships-Mexico Championship in Mexico City.
DeChambeau carded an 8-under-par 63 at Club de Golf Chapultepec to leave him at 11-under 131 through two rounds, one stroke ahead of Patrick Reed and South Africa's Erik van Rooyen.
The low round of the tournament came from van Rooyen, who shot a course-record-tying, 9-under 62 on Friday. The impressive performance occurred on his 30th birthday.
Reed posted a second-round 63.
Justin Thomas (5 under on Friday) and Japan's Hideki Matsuyama (7 under) share fourth place at 9 under.
DeChambeau started on the back nine and was 2 under on the day at the turn before birdieing Nos. 1-3 and Nos. 5-7.
"When you have days like that you can't help but smile out there," DeChambeau said. "I just threw my hands up in the air. I mean, c'mon. Making those putts the way I did, striking the ball as I did, it was surely a joy out there.
"The confidence has got to be high and it is high. Everything's going pretty well, firing on all cylinders."
Van Rooyen amassed nine birdies and no bogeys, starting his round with back-to-back birdies and later adding a stretch of four in a row. He birdied all three par-5 holes.
An eagle midway through the first round of the tournament changed the fortunes of van Rooyen, who had been six pars and three bogeys to that point.
"I want that little spark, and I guess that chip-in on (No. 1 on Thursday), that was it," van Rooyen said, according to GolfWorld.com. "All of a sudden you've got a little bit of positive momentum, you make a putt or two, and you trust yourself and the confidence is there, and things just flow from there. ...
"When you shoot 9 under, everything's going well. What a way to kick off the 30s."
Reed ran off four birdies in a row on the front nine, and he had five more birdies in a seven-hole span on the back nine. He had one bogey.
"The putter was working," Reed said, according to Reuters. "What you see is not always what you get here."
World No. 1 Rory McIlroy of Northern Ireland, who is bidding to complete a career sweep of the WGC events, holds sixth place at 8 under after a 2-under effort on Friday. At 1 under par for the day through 13 holes, McIlroy birdied three of the next four holes to salvage his round.
There is no cut in the 72-player tournament, with the golfers competing for a $1.82 million share of the $10.5 million purse.
--Field Level Media