World number one Rory McIlroy admitted he had enjoyed two pieces of good luck after claiming his second major title in four weeks and a third win in succession.
In a thrilling, weather-affected climax to the US PGA Championship on Sunday, McIlroy carded a closing 68 at Valhalla to finish 16 under par - one shot ahead of Phil Mickelson after a remarkable final day which finished in near-darkness in Louisville after a rain delay of almost two hours.
Rickie Fowler and Henrik Stenson had been part of a three-way tie for the lead with Mickelson on the back nine but dropped shots on the closing stretch to finish two behind McIlroy.
McIlroy started the day with a one-shot lead but dropped two shots in his first six holes and trailed Fowler by three as he reached the turn, only to get back into contention with an eagle on the 10th.
"The ball flight was probably around 30 feet lower than I intended and the line of the shot was probably around 15 yards left of where I intended," McIlroy admitted. "It was lucky, it really was.
"You need a little bit of luck in major championships to win and that was my lucky break. I didn't hit a very good shot there but it worked out well and I made eagle from it."
The second piece of luck came when McIlroy's tee shot on the 18th stopped just short of a water hazard, Phil Mickelson and Rickie Fowler in the group ahead having stood aside on the fairway to allow the final pair to tee off.
"I want to thank Phil and Rickie for letting us tee off, if they hadn't done that we might not have been able to get it done," McIlroy said. "It showed a lot of sportsmanship and class from those two guys."
McIlroy is the first player since Padraig Harrington in 2008 to win back-to-back majors, his victories in the Open Championship and US PGA also sandwiched by a first World Golf Championship win in the Bridgestone Invitational last week.
Lifting the Wanamaker Trophy for the second time also makes the Northern Irishman the third youngest player after Tiger Woods and Jack Nicklaus to win four majors, just one less than the total won by the late Seve Ballesteros and two behind Nick Faldo.
"It's been just incredible," McIlroy said. "I didn't think in my wildest dreams I would have a summer like this. I just played the best golf in my life."
McIlroy, who won the 2011 US Open and 2012 US PGA by eight shots and was six clear going into the final round of the Open, added: "I gutted it out today, it was a little different to my previous major wins. I think I showed a lot of guts to get the job done."
Mickelson did not appear happy with the decision to allow McIlroy and Bernd Wiesberger to hit their approach shots to the 18th but added: "It didn't affect the outcome, I think.
"It's not what we normally do but it's not a big deal. It's a courteous thing to let the guys tee off in case they blow the horn. It gave everyone a chance to finish just in the nick of time."
Fowler has now finished fifth, second, second and third in the year's four majors but acknowledged he had let slip his first real chance to win.
"This is the first one that hurts," Fowler said. "The performance in the majors is something I can be proud of but Rory has been a deserving champion every time. We will see if we can get one away from him at some point."