Rory McIlroy won his first major at the 2011 US Open-5 M Hughes (Can), L Oosthuizen (SA), R Henley (US); -3 R McIlroy (NI), B DeChambeau (US); -2 S Scheffler (US), J Rahm (Spa), M Wolff (US)Selected others: -1 D Johnson (US), X Schauffele (US); E P Casey (Eng), I Poulter (Eng), B Koepka (US), J Thomas (US); +1 L Westwood (Eng), R Bland (Eng)Rory McIlroy and Bryson DeChambeau made their move but Richard Bland's challenge faded as the US Open's third round set up a thrilling final day.
Louis Oosthuizen holed an incredible 50ft eagle putt on the 18th to take a share of the lead with Russell Henley and Mackenzie Hughes on five under.
McIlroy, champion in 2011, shot a four-under 67 and is two back alongside defending champion DeChambeau (68).
Joint halfway leader Bland carded a 77 to sit on one over at Torrey Pines.
The 48-year-old Englishman - who won his first European Tour title in his 478th event in May - had shared the 36-hole lead with Henley at just his second US Open.
The chasing pack features 17 players within five shots of the lead and is stacked with potential winners.
World number three Jon Rahm recovered from a double bogey on the 14th to post a 72 and end on two under, while top-ranked Dustin Johnson is one further adrift after a 68.
McIlroy celebrates anniversary of first US Open title in style
Exactly 10 years to the day after McIlroy won his first major, the 2011 US Open aged just 22, the Northern Irishman rolled back the years as his challenge in 2021 gathered momentum.
He birdied the second and 10th then holed a 30-yard chip from the rough on the 12th to get to two under par. Another birdie followed on the par-five 13th after his 270-yard second shot cannoned off the flagstick.
McIlroy fell back slightly after a wayward drive into a hazard led to his solitary bogey of the round on the 15th but he rallied to birdie the par-five 18th and put himself firmly in the mix.
"It's the best I've played all week," he told Sky Sports. "I stayed really patient and I feel like that patience was rewarded on the back nine."
McIlroy, who won the last of his four major titles at the 2014 US PGA Championship, added that another US Open title would "mean an awful lot" to him, saying he was "just so happy" to have given himself another chance.
"It's felt like a while since I've had a chance to win a major championship going into Sunday," he continued.
"It's not going to be quite as easy as it was 10 years ago but my game feels good and I'll try to do the same again."
Earlier, Ian Poulter sent a reminder to European Ryder Cup captain Padraig Harrington of his ability with a three-under 68 to end the day on level par.
Fellow Englishman Paul Casey is also level after a birdie on the 18th rounded off an excellent 67.
DeChambeau thrives as Koepka falters
Defending champion Bryson DeChambeau was two over after the first round at Torrey PinesBland, 48, said he wanted to take on the "gym-goers" over the weekend, but it was those athletic, younger players who made moves as Saturday unfolded.
DeChambeau made the most impressive move as his 'bomb and gouge' approach helped him post his first bogey-free round in a major; birdies on the first, sixth and 13th left him looming dangerously in joint fourth.
The 27-year-old has been having an ongoing spat with two-time US Open champion Brooks Koepka on social media and said he is "looking forward" to the two of them playing together at some point.
"You've got guys going back and forth on both sides saying 'Team Bryson', 'No, no, no, Team Brooks'. It's really cool, I think it's fun," DeChambeau said of the supposed feud between the two.
"I would love for us to be paired," he added. "Give the fans what they want. I think it would be awesome. We've both got to play well at the same time and I certainly look forward to that day."
Koepka struggled to make anything happen on Saturday and he countered three birdies with three bogeys to finish the day as he started on level par.
Henley also had a mixed bag with four birdies and four bogeys in a 71 as he failed to break clear of the field. His biggest lead was two shots but he played the closing seven holes in over over par to allow Hughes and Oosthuizen to catch him.
The American's day went much better than Bland's though as the Englishman, who hit 10 of 14 fairways off the tee - the third best of the day - struggled with his approach shots in a bogey-ridden showing which culminated in an unfortunate visit to water on the 18th.
Henley managed to stay in the lead, where he had been all day, and he salvaged par despite visiting two bunkers on his way down the final hole.
He was joined in the lead late on by 2010 Open champion Oosthuizen, who suddenly shot to the top of the leaderboard after his impressive eagle putt ended an otherwise streaky round of three birdies and four bogeys.
Canada's Hughes - who failed to make the cut in his three previous US Open appearances - also had an eagle in his three-under 68.
The 30-year-old's effort on the 13th lifted him into joint second and he moved up to a share of top spot with a birdie on the 18th.
