Image 1 of 7: Fans in the gallery on the first tee during the third round of the 96th PGA Championship, at Valhalla Golf Club in Louisville, Kentucky. Photo / Getty Images
The 25-year-old fromNorthern Ireland will play in the final group at Valhalla with the most surprising player in the field - Austria's Bernd Wiesberger.
The European Tour regular matched the best round of the week with a 65, leaving him a stroke back.
Rickie Fowler is right in the thick of things again, shooting 67 and two shots off the pace.
He'll play in the next-to-last group with Phil Mickelson, who birdied four of the last five holes. He was three shots back with Jason Day.