Hideki Matsuyama capped a furious finish at the Memorial by holing out from 130 yards for an eagle that sent him to a 7-under 65 and a share of the lead with Joaquin Niemann and Abraham Ancer.
Matsuyama, who won the Memorial in 2014, was in the middle of the pack until he made four straight birdies starting on the 13th hole, and then made his eagle on the 17th hole.
"As the round went along, I played better and better," said Matsuyama, who got his first PGA Tour win at the Memorial four years ago.
Tiger Woods also had a strong finish with three straight birdies late in his round, but all that did was get him back to even par, leaving him seven shots behind in a tie for 47th.
"I fought back and I didn't really have much starting out," Woods said. "Didn't really feel my swing very well, and consequently I hit it both ways — mainly left. I wasn't rotating very well. Made a few tweaks, a few changes, made a couple of birdies, made a couple of putts, and lo and behold, I finished at even par. I know it's a long way back, but at least I've got a fighting chance."
Justin Thomas, in his debut as the No. 1 player in the world, took a double bogey on the par-5 seventh near the end of his round and had to settle for a 72.
Also at 72 was Dustin Johnson, who made nothing but pars on the back nine and failed to birdie any of the par 5s.
... Ariya Jutanugarn, Sarah Jane Smith and Jeongeun Lee each shot a 5-under 67 to share the first-round lead at the U.S. Women's Open at Shoal Creek.
