Bryson DeChambeau of the United States follows his tee off at the 10th hole during the second round for the WGC-Mexico Championship tournament at the Chapultepec Golf Club in Mexico City, on Friday. (AP photo)

He wasn’t alone Friday in making birdies, although Rory McIlroy would like to have joined the party.

DeChambeau made seven birdies in an eight-hole stretch at Chapultepec Golf Club for an 8-under 63, giving him a one-shot lead over Erik van Rooyen of South Africa and Patrick Reed at the halfway point of this World Golf Championship. DeChambeau was at 11-under 131.

Van Rooyen, who played college golf at Minnesota, celebrated his 30th birthday by making nine birdies to tie the course record with a 62. Reed made five birdies on the back nine for a 63

Justin Thomas ran off four straight birdies to end the back nine, and then holed a 35-foot eagle putt to build a three-shot lead through 10 holes. That was gone in a matter of four holes as player after player kept rolling in putts on a day with much less wind and far better scoring. The average score 70.28, more than two shots better than Thursday.

Bryson DeChambeau looks at his ball after his shot from a bunker at the first green during the first round of the WGC-Mexico Championship tournament at Chapultepec Golf Club in Mexico City on Thursday. (AP photo)

Hideki Matusyama was 9 under for his round through 15 holes and had a 20-footer birdie attempt from the fringe on the par-3 seventh. He missed that 3 feet to the left, then missed the next one. He bogeyed the next hole, too, and had to settle for a 64. That left him at 9-under 133, along with Thomas, who had to settle for a 66.

McIlroy wasn’t so fortunate. Staked to a two-shot lead at the start of the day, he opened with eight straight pars, didn’t make a birdie until his 12th hole and fell six shots behind at one point. Two birdies at the end gave him a 69, and the world’s No. 1 player was only three shots behind.