Rory McIlroy was not having it all his own way as he looked to claim a second major title in four weeks and third win in a row in the 96th US PGA Championship.
McIlroy took a one-shot lead into the third round at a soggy Valhalla which seemingly played into his hands, but the big-hitting world number one was struggling to reproduce the form which saw him claim the Open Championship at Royal Liverpool and a first WGC title on Sunday.
With six holes of his round remaining, the 25-year-old was tied for the lead with playing partner Jason Day and American pair Rickie Fowler and Ryan Palmer, with Jim Furyk, Bernd Wiesberger, Mikko Ilonen and Louis Oosthuizen all a shot back.
McIlroy's fellow Northern Irishman Graeme McDowell felt the course was playing more like a regular PGA Tour event than a major championship, but the final pairing of McIlroy and Day were soon scrambling for dramatic pars.
Day hooked his tee shot on the second so badly that it cleared Floyd's Fork, the creek running down the left-hand side of the hole, and found deep grass on the far side.
Television commentator David Feherty initially looked to be searching for the ball in order for Day to work out where he could take a penalty drop, but the Australian then sent his caddie Colin Swatton to wade through the creek to assist.
When the ball was found in a good enough lie for Day to be able to play it, the 26-year-old then took his shoes and socks off as well and made the journey across to the other side.
Instructing Swatton to "throw me a pitching wedge", Day duly hacked out of the rough, pitched onto the green and holed from 12 feet for a remarkable par.
Two holes later it was McIlroy's turn to escape with a par after pulling his drive into a hazard on the par-four fourth, which had been reduced to 292 yards to allow players to try to drive the green.
After taking a drop McIlroy pitched to 11 feet and holed the putt, although he was joined in the lead by Day who was left with a tap-in birdie after missing from close range for an eagle.
Both players then made birdie on the fifth but McIlroy reclaimed the lead when Day bogeyed the sixth after a wild drive and the three-time major winner was two clear when he holed from five feet on the par-five seventh for birdie.
However, McIlroy duffed his chip from the edge of the eighth green to drop his first shot of the day and it looked like he would drop another when he had to play his second shot on the ninth with his feet in sand and his ball resting on the top of a fairway bunker.
But after his approach flew over the green, McIlroy hit an excellent chip to five feet and holed the putt and then holed from 11 feet on the par-five 10th to reclaim the lead.
Another duffed chip on the 12th meant that lead did not last long and a tense finish was on the cards.