Phil Mickelson is in position for a first US Open title after the finishing the third day one shot in the lead after another eventful day at Merion.
The 43-year-old five-time runner-up shot 70 to finish one under, though he will be expecting a hotly contested final round on Sunday from the likes of Luke Donald and Charl Schwartzel.
The Englishman bogeyed the 17th and double bogeyed the 18th to drop back to one under after looking in form for much of his 71, though he insisted he felt good and was confident of challenging Mickelson, despite his late slip on Saturday.
"I should have done better," said Donald, who is looking to become the first Englishman to win the US Open since Tony Jacklin in 1970.
"It was disappointing but I'll take the positives out of today, a really solid 16 holes of golf that I played and I'm only two back.”
South African Schwartzel was another, of many, to drop shots on the last two holes in a decent round of 69 that left him level and one off the lead.
Four birdies early in the round would have had the 28-year-old pleased with how solid he was looking until the 17th and 18th, but there is plenty of encouragement for him going into Sunday’s play.
Conditions at Merion are expected to be testing on Sunday, though will not be as extreme as we have seen since Thursday, where the damage was done for many of the players.
Lee Westwood ended on six over after a promising round of 69 and will be hoping for similar on Sunday to push further up the leader board, though fellow Briton Rory McIllroy was not able to make a similar recovery.
The champion from 2011 could not find his best form in shooting a 75, with seven bogeys in all and only two birdies.
McIllroy was joined on eight over by American Jason Dufner, whose four bogeys from the first five holes meant his day was unlikely to be a happy one and he finished on 73.
US Open leaderboard after day three:
-1: Mickelson (US) Level: Mahan (US), Schwartzel (SA), Stricker (US) +1: Rose (Eng), Donald (Eng), Horschel (US) +2: Day (Aus)
Others: +6: Westwood (Eng) +8: McIlroy (NI) Dufner (USA)