"I felt stressed all day, because I knew every shot had 'big penalty' written all over it," Mahan said. "It was a really tough day. There wasn't an easy shot out there. One of those rounds where it could go south pretty fast, so you've got to grind it out and find a way to get a number up there and get to the weekend."
Only three players broke par in the second round. No one shot in the 60s. The average score was a fraction under 76.
"I don't think I've played in conditions this difficult in the U.S.," Graeme McDowell of Northern Ireland said after a 71 that left him one shot behind. "It's an Open Championship day. It's a real Friday afternoon at St. Andrews in 2010 before they called it. It was hard out there really, really hard."
Rory McIlroy (74), Francesco Molinari (75) and Jamie Donaldson of Wales (70) also were one behind at even-par 144.
Tiger Woods hit three balls in the water and scraped out a 73, thanks in part to a 90-foot birdie putt on the par-3 fourth hole. Phil Mickelson made back-to-back double bogeys, and then laid on his back along the bank of the fourth tee during a long wait. He got up, hit into the water and made another double bogey. Lefty shot 75.
Both were still in the mix, only six shots behind.
Puerto Rico Open
James Driscoll matched the Puerto Rico Open record with a 9-under 63 to take a one-stroke lead after the second round. Playing in wind gusting to 20 mph after morning rain at Trump International in Rio Grande, Driscoll had an eagle and seven birdies in his bogey-free round. He had a 12-under 132 total.
PGA Tour rookie Chesson Hadley was second after a 65.
Patrick Reed -1
Dustin Johnson -1
Matt Kuchar -1
Hunter Mahan -1
Four tied E