Defending champion Rory McIlroy failed to find the fast start he was hoping for when the 97th US PGA Championship resumed at Whistling Straits on Friday.
Starting from the 10th in benign conditions, McIlroy knew the first few holes of the back nine provided opportunities to reduce his five-shot deficit to overnight leader Dustin Johnson.
However, the world number one missed from 18 feet for birdie on the 10th and was unable to get up and down for birdie on the par-five 11th after a badly pulled approach.
McIlroy, who is playing his first event since the US Open in June following a seven-week injury lay-off, never threatened to hole a long birdie attempt on the 12th and remained one under par, six behind new leader David Lingmerth.
Lingmerth had carded an impressive 67 in the tougher afternoon conditions on Thursday and carried on where he left off with birdies on the first and third to move a shot ahead of Johnson, who was among the later starters.
McIlroy’s frustration was compounded by seeing playing partner Zach Johnson birdie the 10th, 11th and 12th, the Open champion holing from 10, 17 and then eight feet to get back to level par.
World number two Jordan Spieth had birdied the 11th but failed to get up and down from a greenside bunker on the 12th to drop back alongside McIlroy on one under.