All the action as it happened from the first round at Olympia Fields.
Defending champion Tiger Woods carded a level-par 70 to be five shots behind surprise leaders Brett Quigley and 53-year-old Tom Watson.
Jay Don Blake
All times BST
0033: Watson receives the adulation of the crowd as he finishes with a par to take a share of the clubhouse lead.
0018: Watson holes another massive putt to take a share of the lead with one more to play.
0010: Garcia drops back to one under after a disappointing bogey at the 18th.
2359: Watson moves to four under with an incredible putt for a birdie at the seventh. The ball stops agonisingly on the lip of the cup, but as Watson walks towards it, the ball obligingly drops in prompting wild cheers from the gallery.
2352: A par from Garcia keeps him in the hunt at two under par.
2333: Toms misses a birdie chance on the 18th to finish with a two-over 72.
2321: Garcia slides a putt by the edge on 15 to drop a shot and fall back to two under.
2309: Beem birdies the 16th and 17th to move to two over.
2307: Watson lies three under with five to play while Garcia rolls in a massive putt on the 14th to move to three under.
2252: Davis drops a shot at the 18th to close with a one-over 71. When he started by going five under after just four holes - eagle, birdie, birdie, birdie - he made the fastest ever start in a US Open.
2247: Quigley is the new clubhouse leader as he closes with a fine 65, one shot clear of the field.
2238: A bogey at the par-four eighth means Damron drops to two under.
2227: A fine bunker shot from Quigley leaves him a six-foot putt to save par on the 17th and maintain his one-shot lead. He duly rolls it in to stay out in front.
2223: Watson moves to three under par to lie just two off the lead. Irwin pulls out with back trouble.
2214: Furyk now has four birdies in five holes after birdieing the fifth as he moves to two under.
2212: Quigley rolls in a birdie putt on the 15th to take the outright lead, while Davis also birdies the hole to move back to level par after a very up-and-down round which saw him as low as five under early on.
2210: Mickelson again fails with a birdie putt, this time on the 5th.
2156: Quigley makes a six-foot putt for par on the 15th to keep a share of the lead.
2142: On the 3rd Furyk rolls in his third birdie in a row to move to one under, while Quigley joins the leaders on four under par.
2139: Perry makes his second birdie in a row as he rolls in the putt at the 2nd.
2137: Watson skips a drive past the hole at the 17th.
2135: Perry produces a good approach at the 2nd - his 11th - after birdieing the hole before.
2125: Furyk moves back to level par with a birdie at the 2nd - his 11th. The veteran Watson moves to two under as he approaches the turn.
2120: Mattiace fails to move within one of the lead as he leads a long birdie putt two feet short at the 17th.
2100: Mickelson manages to just avoid a bunker on the 7th but has now only hit two fairways so far this round.
2054: Garcia misses the chance to close on the lead as he three-putts the sixth and only makes par. The Spaniard's putting has let him down recently and it comes back to haunt him once again.
2039: Davis three-putts the 10th to fall back to two under.
2035: Mickelson continues his erratic round by dropping a shot.
2033: Clarke bidies the 17th to move back to level par.
2028: Garcia gets the weight correct on his birdie putt at the fifth but sends it two feet wide of the hole to stay two under.
2022: After getting a free drop out of a sprinkler head on the fifth Garcia sends his second onto the front edge of the green to give himself a long putt for birdie.
2010: Garcia consolidates his fine start by birdieing the third and fourth to stay at two under.
2005: Two-time champion Lee Janzen gives himself a birdie chance on the 15th.
1953: Amateur Hunter Mahan, who was just one shot off the lead, drops away after carding an eight at the 5th.
1942: Blake cards a 66 to join Leonard as the clubhouse leader on four under. Garcia continues his fine start to his round with a second birdie in the first two holes.
1935: Hale Irwin stabs a tentative putt wide on the 3rd to drop back to level par.
1925: Young Spaniard Sergio Garcia gets his round underway with an easy birdie at the 1st.
1915: Davis cards a double bogey at the fifth to drop back to three under par.
1903: Montgomerie drops a shot at his last hole of the day - the 9th - to finish on one under while Harrington does the same at the 18th for the same total.
1800-1900: Woods closed with a level-par 70 while playing partner Els was one shot better off.
Qualifier Brian Davis started eagle, birdie, birdie, birdie to lie an astonishing five under after just four holes. It was the fastest-ever start in a US Open.
1700-1800: Woods collected an eagle on the 6th - his 15th - as he finally came to life and moved sub par for the first time for the tournament.
Harrington and Montgomerie maintain their steady starts with some solid golf.
1600-1700: Woods was playing well and giving himself birdie chances but he could not hole any putts.
Harrington produced a birdie at the 10th to move back within a shot of the lead, which was held by Montgomerie.