Zach Johnson celebrated his first sub-70 round in eight US Open appearances as he joined the logjam on two under with a 69 on Friday.

The 2007 Masters champion will go into the weekend nine shots behind runaway leader Rory McIlroy, but he is confident he can close the gap.

Johnson got to four under after a front-nine 32 which included two birdies and an eagle at the sixth, but he bogeyed 10 and 14 as his putter went cold on the inward half.

"I'm just going to play my game," he said. "I can't control the leaderboard. I certainly can't control what Rory is doing or anybody else.

"The way I look at it, the pressure is off me. I'm not the one that's supposed to win it right now.

"I'm going to go out and do the same thing. I hit a lot of shots close today, just didn't take advantage of it.

"I'm looking forward to the weekend, hitting it well. It's going to be fun. Hopefully Rory doesn't get too crazy on us, but if he does I'll be playing for second place, which is not bad, either."