Southampton - Dustin Johnson surrendered a four-shot lead to fall into a four-way tie atop the US Open leaderboard as Shinnecock Hills again battered the world's best golfers on Saturday.
World No 1 Johnson closed with a three-putt bogey at the 18th in a seven-over par 77 that left him tied on three-over par 213 with Daniel Berger, Tony Finau and defending champion Brooks Koepka.
Berger and Finau teed off early and stormed up the leaderboard with four-under par 66s, playing before sunshine and sea breezes dried out the course.
By the time the leaders teed off, Shinnecock's greens were hard and fast, and players could only watch as good approach shots rolled off the domed putting surfaces and lightly tapped putts skated past the hole.
The sight raised the spectre of the 2004 US Open at Shinnecock, when weekend wind dried the course and rendering some of the greens virtually unplayable by Sunday.
"Frankly, we missed it with the wind," admitted US Golf Association chief executive Mike Davis. "The speed of the greens was too much for the wind we had. It was a very tough test, but probably too tough this afternoon."
Johnson, four-under and leading by four heading into the round, was in trouble early with his first double bogey of the week at the par three second. His four bogeys on the front nine included three in a row at six, seven and eight.
"I didn't feel like I played badly at all," Johnson said. "Seven-over usually is a terrible score, but with the greens the way they got this afternoon - they were very, very difficult."
As he struggled, England's Justin Rose and Sweden's Henrik Stenson tussled for the lead.
But Rose had three bogeys in a row at eight, nine and 10 and bogeyed two of his last three to come in with a 73 that left him tied for fifth on 214.
"I've never seen golf course change that quickly," Rose said. I don't think the course was necessarily over the line, but pin placements relative to speed and firmness ... the edge was reached."
Stenson capped his four-over 74 with a bogey at 18 and was alone in sixth on 215.
Despite all the difficulties, Johnson steadied himself to arrive at the 18th tee with a one-stroke lead. His approach from the fairway bounced near the pin and rolled 17 feet past. His first putt raced past the hole and his par attempt burned the edge but didn't drop.
Koepka, who had two birdies and four bogeys in his two-over 72, voiced concern that the golf course would hold up through the final round.
"I hope these greens are good enough to play tomorrow," said Koepka, who lifted the trophy at Erin Hills last year with a record-equalling 16-under par total.
"They're very borderline right now to be honest with you."
Finau and Berger both notched six birdies in their four-under efforts. The day's only other sub-par round was Kiradech Aphibarnrat's 68, which put the Thai into a tie for seventh on six-over.
But two-time PGA Tour winner Berger had seen the danger developing during his early round.
"You hit one by, three feet past the hole and it's going 40 yards away from the green," he said.
That may have been what led to Phil Mickelson's astonishing performance at the 13th green - where after watching his bogey putt roll past the cup and head down a hill he ran over and batted the still moving ball back toward the hole.
With the two-stroke penalty Mickelson took a sextuple bogey 10.
WATCH: Mickelson throws 'putting tantrum' at US Open
Playing partner Andrew Johnston called it a "moment of madness" but Mickelson, a five-time major champion celebrating his 48th birthday on Saturday, insisted it wasn't just a display of petulance.
"Look, I don't mean disrespect to anybody," he said. "I know it's a two-shot penalty. At that time, I just didn't feel like going back and forth and hitting the same shot over.
"It's meant to take advantage of the rules as best as you can," he said.
Third-round scores on Saturday in the 118th US Open Golf Championship at Shinnecock Hills (USA unless noted, par-70):
213 - Daniel Berger 76-71-66, Tony Finau 75-72-66, Brooks Koepka 75-66-72, Dustin Johnson 69-67-77
214 - Justin Rose (ENG) 71-70-73
215 - Henrik Stenson (SWE) 71-70-74
216 - Kiradech Aphibarnrat (THA) 76-72-68, Patrick Reed 73-72-71, Jim Furyk 73-71-72
217 - Brian Gay 73-74-70, Dylan Meyer 77-69-71, Tyrrell Hatton (ENG) 75-70-72, Branden Grace (RSA) 76-69-72, Ian Poulter (ENG) 69-72-76, Charley Hoffman 71-69-77
218 - Gary Woodland 79-69-70, Zach Johnson 73-73-72, Xander Schauffele 72-74-72, Bryson DeChambeau 76-69-73, Justin Thomas 74-70-74, Matthew Fitzpatrick (ENG) 73-70-75
219 - Webb Simpson 76-71-72, Francesco Molinari (ITA) 75-72-72, Paul Casey (ENG) 73-73-73, Ryan Fox (NZL) 73-72-74, Russell Knox (SCO) 73-71-75, Russell Henley 69-73-77, Tommy Fleetwood (ENG) 75-66-78, Scott Piercy 69-71-79
220 - Brendan Steele 72-73-75, Rafa Cabrera Bello (ESP) 73-71-76, Charles Howell 71-72-77
221 - Jhonattan Vegas (VEN) 76-72-73, Brandt Snedeker 72-76-73, Steve Stricker 73-75-73, Matt Parziale (USA) 74-73-74, Li Haotong (CHN) 79-68-74, Chris Naegel 73-73-75, Louis Oosthuizen (RSA) 74-72-75, Pat Perez 73-71-77, Alex Noren (SWE) 72-72-77, Marc Leishman (AUS) 74-69-78
222 - Bill Haas 76-72-74, Matthieu Pavon (FRA) 71-77-74, Luis Gagne (CRC) 73-74-75, Peter Uihlein 75-72-75, Sam Burns 71-76-75, Patrick Cantlay 75-71-76, Brian Harman 74-70-78
223 - Dean Burmester (RSA) 75-73-75, Aaron Baddeley (AUS) 74-72-77, Will Grimmer 73-72-78, Jason Dufner 70-74-79
224 - Cameron Wilson 75-73-76, Hideki Matsuyama (JPN) 75-70-79, Jimmy Walker 75-70-79, Mickey DeMorat 72-72-80
225 - Kevin Chappell 75-72-78, Calum Hill (SCO) 75-69-81, Tyler Duncan 77-67-81
226 - Tim Wilkinson (NZL) 76-72-78, Ross Fisher (ENG) 76-71-79, Rickie Fowler 73-69-84
227 - Phil Mickelson 77-69-81, Patrick Rodgers 72-72-83
228 - An Byeong-hun (KOR) 71-76-81, Andrew Johnston 73-73-82