American duo Patrick Reed and Jordan Spieth are joint-top of the US Open on five-under-par after day two at Chambers Bay.
Spieth made the early move as he struck a round of 67 to progress up the leaderboard, on a day where several players went backwards.
Reed, who started the day in third place on four-under-par, had a mixed round of 69 as he hit five birdies, six bogeys and an eagle.
The 24-year-old looked set to be the overnight leader, but he bogeyed the last hole.
Dustin Johnson, who was the co-leader after day one, and South Africa's Brandon Grace sit one shot back on four-under-par, while Joost Luiten leads the European charge on three-under.
World number one Rory McIlroy endured another frustrating day as he hit a round of 72 and sits on four-over-par, while Tiger Woods bowed out of the tournament as he failed to make the cut following a round of 76.
England's Paul Casey and Scotland's Marc Warren lead the British charge on one-over-par.