Springfield - Rory McIlroy, Dustin Johnson and Phil Mickelson were among the stars humbled by Baltusrol in Thursday's opening round of the PGA Championship, leaving unheralded Jimmy Walker to seize the lead.
Walker, a 37-year-old American who missed the cut in three of his past four majors, fired a five-under-par 65 for a one-stroke lead over Britain's Ross Fisher, two-time major winner Martin Kaymer of Germany and Argentina's Emiliano Grillo.
"All in all it was a great day," Walker said. "I feel like I've prepared and I'm ready to go this week. It's nice that's what showed."
New British Open champion Henrik Stenson of Sweden shared fifth on 67 with Britain's Andy Sullivan and Americans Harris English and James Hahn.
"I'm very happy," Stenson said. "It was a solid round and a good start. I couldn't ask for anything more than this."
Top-ranked defending champion Jason Day was among 12 players on 68. The Australian hung three off the pace despite fighting fatigue and illness and playing only one practice round.
"Missed a lot of opportunities. I haven't had the greatest putting display," Day said. "To hit it where I wanted and execute like I did, really positive going into the next three days."
But several of the favourites stumbled over the first 18 holes at the 7,428-yard layout.
Johnson, who won his first major at last month's US Open, had two double bogeys, four bogeys and a lone birdie in a 77.
Fourth-ranked McIlroy, a four-time major winner, fired a birdie-free 74, his worst-ever start in an event he has won two of the past four years.
"I know my game is there, to keep giving myself chances," McIlroy said.
"Hopefully I'm not shutout tomorrow. I can't remember the last time I went without a birdie. I'll stay as patient as I can and hopefully turn it around."
McIlroy was on the practice green five hours after his round seeking answers.
"I just really struggled on the greens. I had a couple chances I didn't convert," McIlroy said. "It just wasn't my day."
Five-time major winner Mickelson, the 46-year-old US left-hander who was British Open runner-up two weeks ago, made four bogeys in his first 11 holes but rallied to finish on 71 -- six adrift alongisde Spain's Sergio Garcia, two-time Masters winner Bubba Watson and reigning Masters champion Danny Willett.
"To come out and hit shots like I hit those first 11 holes was very disappointing," Mickelson said. "I'm proud that I hung in there, fought and got three back coming in.
Third-ranked Jordan Spieth took a double bogey at seven but birdied the par-3 16th and par-5 18th to finish on 70.
"Held strong, made a couple par saves. Pleased to grind out even par," Spieth said. "I'm only five back. I post something tomorrow I'm definitely back in it."
Groundskeepers were spraying water on certain greens between groups to keep putting surfaces from burning out in the heat, although thunderstorms are forecast the next three days.
Walker, a back-nine starter, followed his lone bogey at the sixth with a 31-foot birdie putt at the seventh to grab the lead.
Two closing pars kept him there and had him pondering possibilities in a year that has already produced three first-time major winners.
"I don't think it's coincidence or anything," Walker said. "They are all good players and it was just a matter of time. So just keep that rolling."
Kaymer made a run of five birdies in seven holes with a lone bogey at the second keeping him from a share of the lead.
"Nothing easy on the golf course," Kaymer said. "I just didn't miss many fairways and therefore, you can create some birdie chances. But at the end of the day you still need to make the putts."
Grillo made a 30-foot birdie putt at the par-3 fourth to highlight his day.
"It's very tricky out there," Grillo said. "If you miss the greens in the wrong spot, you're going to have trouble getting up and down. It's a very hard course."
Fisher overcame humidity that had him consuming more water than he ever expected.
"You have to drink way more than you think. Majors are a tough, long, gruelling week," Fisher said. "It's a good start but there's a long way to go."
Scores on Thursday after the opening round of the 98th PGA Championship at par-70 Baltusrol Golf Club (USA unless noted):
65 - Jimmy Walker 33-32
66 - Emiliano Grillo (ARG) 31-35, Ross Fisher (ENG) 32-34, Martin Kaymer (GER) 33-33
67 - Harris English 34-33, James Hahn 33-34, Andy Sullivan (ENG) 31-36, Henrik Stenson (SWE) 34-33
68 - K.J. Choi (KOR) 35-33, David Lingmerth (SWE) 34-34, Scott Hend (AUS) 33-35, Rickie Fowler 35-33, Robert Streb 33-35, Vaughn Taylor 34-34, Brooks Koepka 34-34, Jason Day (AUS) 33-35, Jhonattan Vegas (VEN) 34-34, John Senden (AUS) 35-33, Russell Henley 34-34, Louis Oosthuizen (RSA) 34-34
69 - Bradley Dredge (WAL) 33-36, Jon Curran 36-33, Hideki Matsuyama (JPN) 34-35, Victor Dubuisson (FRA) 33-36, Chris Wood (ENG) 34-35, Gregory Bourdy (FRA) 34-35, Justin Thomas 34-35, Paul Casey (ENG) 36-33, Lee Westwood (ENG) 34-35, Jamie Donaldson (WAL) 33-36, Colt Knost 33-36, Rich Beem 35-34, Steve Stricker 33-36, Danny Lee (NZL) 35-34, Webb Simpson 34-35
70 - Jason Kokrak 33-37, Brian Stuard 36-34, Aaron Baddeley (AUS) 35-35, Soren Kjeldsen (DEN) 34-36, Branden Grace (RSA) 34-36, Adam Scott (AUS) 34-36, Bill Haas 34-36, Yuta Ikeda (JPN) 35-35, Andrew Johnston (ENG) 35-35, Alex Noren (SWE) 35-35, Thorbjorn Olesen (DEN) 35-35, Jordan Spieth 36-34, Justin Rose (ENG) 35-35, Patrick Reed 37-33, Russell Knox (SCO) 33-37, Kiradech Aphibarnrat (THA) 35-35, William McGirt 36-34, Daniel Summerhays 36-34, Kyle Reifers 36-34
71 - Patton Kizzire 37-34, Freddie Jacobson (SWE) 35-36, Jason Bohn 36-35, Daniel Berger 35-36, Tyrrell Hatton (ENG) 34-37, Kevin Kisner 35-36, Padraig Harrington (IRL) 35-36, Marcus Fraser (AUS) 33-38, Zach Johnson 36-35, Kevin Na 33-38, Phil Mickelson 32-39, Jamie Lovemark 38-33, Hideto Tanihara (JPN) 36-35, Ryan Palmer 35-36, Rob Labritz 34-37, Jason Dufner 35-36, Francesco Molinari (ITA) 34-37, Brendan Steele 34-37, Sergio Garcia (ESP) 34-37, Bubba Watson 36-35, Marc Leishman (AUS) 36-35, Thomas Pieters (BEL) 37-34, Danny Willett (ENG) 35-36, Ryan Moore 34-37, Song Young-Han (KOR) 32-39, Kim Si-Woo (KOR) 34-37
72 - Kristoffer Broberg (SWE) 36-36, Billy Hurley 34-38, Rikard Karlberg (SWE) 37-35, Roberto Castro 37-35, Omar Uresti 34-38, Greg Chalmers (AUS) 34-38, Rafael Cabrera-Bello (ESP) 37-35, George Coetzee (RSA) 34-38, Ryan Helminen 37-35, Nicolas Colsaerts (BEL) 37-35, Michael Block 37-35, Harold Varner 35-37, Johan Kok 36-36 (USA*), Kevin Chappell 35-37, Scott Piercy 38-34, Rich Berberian 35-37, Matthew Fitzpatrick (ENG) 36-36, Billy Horschel 36-36, Luke Donald (ENG) 36-36, Yang Yong-Eun (KOR) 36-36, Shane Lowry (IRL) 35-37, An Byeong-Hun (KOR) 37-35, Thongchai Jaidee (THA) 36-36, Joost Luiten (NED) 36-36, Cameron Tringale 35-37, Ben Polland 36-36
73 - Wang Jeung-Hun (KOR) 36-37, Matt Dobyns 33-40, Ernie Els (RSA) 36-37, David Muttitt 35-38, Smylie Kaufman 34-39, Zac Blair 36-37, Brandt Snedeker 36-37, Keegan Bradley 37-36, Rod Perry 35-38, Gary Woodland 37-36, Anirban Lahiri (IND) 36-37, Charl Schwartzel (RSA) 38-35, Peter Malnati 36-37
74 - Chris Kirk 34-40, Brian Gaffney 37-37, Darren Clarke (NIR) 38-36, Vijay Singh (FIJ) 36-38, John Daly 35-39, Matt Jones (AUS) 36-38, Rory McIlroy (NIR) 35-39, David Toms 39-35, Matt Kuchar 39-35, Jim Furyk 37-37, Graeme McDowell (NIR) 37-37, Mitch Lowe 37-37, Bryce Molder 37-37
75 - Mark Brown 37-38, J.B. Holmes 38-37, Charley Hoffman 34-41, Jonas Blixt (SWE) 38-37, Fabian Gomez (ARG) 37-38, Bernd Wiesberger (AUT) 40-35, Kevin Streelman 35-40
76 - Wyatt Worthington 39-37, Joe Summerhays 38-38, Rocco Mediate 39-37
77 - Tommy Sharp 40-37, Josh Speight 38-39, Troy Merritt 40-37, Shaun Micheel 38-39, Tony Finau 39-38, Jim Herman 38-39, Lee Soo-Min (KOR) 39-38, K.T. Kim (KOR) 39-38, Dustin Johnson 38-39
78 - James Morrison (ENG) 36-42, Rick Schuller 38-40
79 - Brandon Stone (RSA) 39-40, Brad Ott 41-38
83 - Brad Lardon 43-40
* Johan Kok is South African-born