Bidding to become the oldest winner in major history, Phil Mickelson will take a slender lead into the final day of the 103rd US PGA Championship after an extraordinary third round at Kiawah Island.
Eight years after claiming his fifth major title in the 2013 Open and 16 years on from winning the US PGA title at Baltusrol, Mickelson produced some vintage golf to surge into a five-shot lead, only to see it wiped out six holes later.
But with two-time winner Brooks Koepka suffering an uncharacteristically nervous finish, Mickelson again found himself in the outright lead after a 70 which veered from the sublime to the ridiculous and back again.
At seven under par Mickelson ended a breathless day a shot ahead of Koepka, who is chasing a third US PGA title in four years just nine weeks after undergoing surgery to deal with a knee cap dislocation and ligament damage.
Former Open champion Louis Oosthuizen lies two shots off the lead after a 72, with American Kevin Streelman another stroke back following a round of 70.
Mickelson and Oosthuizen began the day in a tie for the lead but that state of affairs did not last long, Oosthuizen three-putting the first before Mickelson clicked into top gear in brilliant fashion.
Aiming to surpass Julius Boros — who was 48 when he won the US PGA in 1968 — as the oldest major winner, Mickelson fired a long iron from 267 yards onto the green on the par-five second and two-putted from 15 feet for birdie.
The 50-year-old left-hander then span his approach from a fairway bunker to within two feet of the pin on the next, holed from 17 feet for another birdie on the sixth and two-putted the par-five seventh for his fourth gain of the day.
A 280/1 outsider at the start of the week, Mickelson amazingly moved five shots clear with a birdie on the 10th, but surprisingly missed from short range for another on the par-five 11th.
Oosthuizen did pick up a shot on 11 and also birdied the 12th for a two-shot swing as Mickelson found sand off the tee on his way to a first bogey of the day.
Oosthuizen looked to have squandered his recent gains when he drove into the water on the 13th, only for Mickelson to amazingly follow him into the hazard.
Oosthuizen’s ball had at least crossed the boundary of the hazard part of the way down the hole and he was able to scramble a bogey, but Mickelson had to hit another ball off the tee on his way to a double bogey.
With his lead down to one, Mickelson showed commendable composure to hit a superb tee shot on the par-three 14th, but was unable to convert the birdie attempt from seven feet.
In the group ahead, Koepka hit a stunning second shot from 284 yards on to the 16th green to set up a birdie to tie the lead, while Mickelson’s wayward drive on the same hole finished under a golf cart’s front tyre.
Koepka then left his birdie putt on the 17th woefully short and did well to save par, but was unable to repeat the feat on the last to hand Mickelson a welcome advantage.
Earlier, Rory McIlroy’s slim hopes of a second US PGA Championship victory at Kiawah Island disappeared.
McIlroy knows all about enjoying runaway wins at the Ocean Course after storming to an eight-shot win in 2012 and that, coupled with his victory in the Wells Fargo Championship a fortnight ago, had seen him installed as pre-tournament favourite.
However, the 32-year-old was never a factor following an opening 75 and again failed to break par despite easier conditions on Saturday, a third round of 74 leaving the four-time Major winner on five over par.
Asked what he needs to improve, McIlroy said: “It’s being a little tidier around the greens, it’s hitting a few more fairways, it’s taking some of your chances when you do hit good iron shots, instead of making the pars, you make the birdies. Just getting some momentum.
“I just feel like I haven’t had any momentum this week. When you start the way I did today with a bogey and then you don’t make a birdie on the second hole, you’re just always trying to play catch up, and it’s hard to on this golf course because there’s very few opportunities where you can be really aggressive.”
Shane Lowry and Pádraig Harrington also failed to make a move on Saturday, both carding one-over-par rounds of 73 to slip back to one over for the tournament.
After making three bogeys in the first 15 holes of his third round, Lowry finally recorded a birdie on the par-five 16th and followed it up with a stunning tee-shot at the tough par-3 17th and a tap-in birdie.
Ryder Cup captain Harrington dipped under par for the tournament after a birdie on the par-5 second but three bogeys and just one more birdie left him over par for his round.
Jordan Spieth might have expected to reduce his deficit to the leaders after a third round of 68 got him back to level par, but with conditions remaining favourable for the later starters, he was off to simply enjoy the Mickelson show.
“It’s Phil, right. It’s theatre,” Spieth said. “I don’t watch golf but I promise you I’m going to turn it on to watch him today. It’s pretty incredible.
“He’s just a great player. He’s one of the best to ever play the game. He’s won a World Golf Championship [event] in the last couple years and he stays relevant all the time.”
Third round scores from the US PGA Championship (USA unless stated, Par 72)
209 Phil Mickelson 70 69 70
210 Brooks Koepka 69 71 70
211 Louis Oosthuizen (Rsa) 71 68 72
212 Kevin Streelman 70 72 70
213 Christiaan Bezuidenhout (Rsa) 71 70 72, Branden Grace (Rsa) 70 71 72
214 Bryson DeChambeau 72 71 71, Joaquin Niemann (Chi) 71 72 71, Gary Woodland 70 72 72
215 Paul Casey (Eng) 71 71 73, Corey Conners (Can) 67 75 73, Sung Jae Im (Kor) 70 72 73
216 Keegan Bradley 69 75 72, Patrick Cantlay 73 73 70, Tony Finau 74 72 70, Matthew Fitzpatrick (Eng) 73 71 72, Rickie Fowler 71 76 69, Harry Higgs 72 71 73, Charley Hoffman 73 70 73, Jason Kokrak 71 72 73, Jordan Spieth 73 75 68, Richy Werenski 71 72 73
217 Joel Dahmen 74 73 70, Pádraig Harrington (Irl) 71 73 73, Billy Horschel 77 72 68, Martin Laird (Sco) 70 73 74, Shane Lowry (Irl) 73 71 73, Hideki Matsuyama (Jpn) 73 68 76, Ian Poulter (Eng) 74 70 73, Scottie Scheffler 72 74 71, Steve Stricker 76 71 70, Will Zalatoris 71 74 72
218 Ben Cook 72 77 69, Carlos Ortiz (Mex) 73 74 71, Patrick Reed 74 75 69, Webb Simpson 75 74 69, Cameron Smith (Aus) 72 73 73
219 Talor Gooch 71 78 70, Tyrrell Hatton (Eng) 71 75 73, Viktor Hovland (Nor) 69 75 75, Collin Morikawa 70 75 74, Alexander Noren (Swe) 77 72 70, Jon Rahm (Spa) 72 75 72, Daniel van Tonder (Rsa) 75 70 74
220 Robert MacIntyre (Sco) 75 73 72, Justin Rose (Eng) 72 75 73, Jason Scrivener (Aus) 73 75 72, Harold Varner III 73 76 71, Lee Westwood (Eng) 73 72 75, Aaron Wise 69 79 72
221 Stewart Cink 71 76 74, Jason Day (Aus) 74 75 72, Emiliano Grillo (Arg) 77 72 72, Tom Lewis (Eng) 71 74 76, Denny McCarthy 73 76 72, Rory McIlroy (NIrl) 75 72 74, Wyndham Clark 75 74 72
222 Abraham Ancer (Mex) 74 72 76, Daniel Berger 79 69 74, Dean Burmester (Rsa) 74 74 74, Russell Henley 78 70 74, Sam Horsfield (Eng) 69 80 73, Matt Jones (Aus) 73 75 74, Chan Kim 75 74 73, Jimmy Walker 73 74 75, Bubba Watson 72 73 77, Danny Willett (Eng) 77 71 74
223 Cameron Davis (Aus) 69 78 76, Tom Hoge 74 75 74, Robert Streb 77 72 74, Matt Wallace (Eng) 73 73 77
224 Harris English 75 74 75, Adam Hadwin (Can) 77 71 76, Brad Marek 73 73 78
225 Byeong-Hun An (Kor) 73 75 77, Lucas Herbert (Aus) 76 72 77, Henrik Stenson (Swe) 73 76 76
226 Rasmus Hoejgaard (Den) 71 76 79, Brendan Steele 75 74 77
227 Garrick Higgo (Rsa) 73 76 78
228 Brian Gay 77 71 80