On Thursday, the 27-year-old Tucson native had seven birdies and three bogeys for a 4-under-par 66 that was good enough for a 3-shot lead with most of the rounds completed from the morning wave. Thompson, who was a rookie on the PGA Tour in 2011, hit eight of 14 fairways, found 8 of 18 greens and converted 4 of 6 sand saves. At the third, he holed out from a greenside bunker for birdie.
"I think it's a real advantage having played here in 2007," Thompson said. "A lot of the players haven't seen the changes to the courses since 1998.
"Knowing, remembering certain spots that I have been in before, you play the course 15, 20 times, you're going to know where to hit it and where not to. And what side of the hole's best." This is Thompson's first U.S. Open since Torrey Pines in 2008, where he finished in a tie for 29th. It was his first major as a professional.
After his round, he said he doesn't mind people looking past his good opening round to Tiger Woods, who sits 3 shots back at 1 under par.
"I've always flown under the radar," Thompson said. "I've always been a player that sort of hangs around. Give Tiger the spotlight. If I do the things that I need to do, I will be there at the end."
Farrell Evans covers golf for ESPN and can be contacted at email@example.com.