Graeme McDowell posted a 72 on day two of the US Open in San Francisco to remain in contention at the upper end of the leaderboard on one over par.
The 2010 champion from Portrush is just two shots behind joint leaders Tiger Woods, David Toms and Jim Furyk.
Defending champion Rory McIlroy is out after rounds of 77 and 73 - his fourth missed out out of five.
"It was not the way I wanted to play but, to be honest, overall I don't feel like I played that badly," he said.
"You really have to be so precise out there. We are just not used to playing this sort of course week-in, week-out.
"You have to adapt and adjust and I was not able to do that very well."
McIlroy had a birdie putt on the last hole to get to eight over, and sneak through to the last two days, but three-putted for a bogey.
After a week off world number two McIlroy returns in the Irish Open at Royal Portrush, where he set an amazing course record of 61 in 2005 when just 16.
McDowell put himself in the running for a second major in northern California with his 72 to reach the halfway stage at one over at the Olympic Club.
The Northern Irishman was alone in second place at two under for most of his round before a late stumble with three bogeys over his last four holes saw him slip back as the wind started to pick up.
"That's what this golf course can do to you in a heart beat," said McDowell.
"To be honest with you, if you had offered me one-over par starting on the first tee yesterday, having seen what I saw yesterday morning, I would have probably snapped your arm off for it.
"I am very happy to be where I am. I made enough birdies to kind of offset some mistakes, which I think is key."