Rory McIlroy faded out of contention as Alex Fitzpatrick grabbed the third-round lead at the Truist Championship in North Carolina.
McIlroy, playing his first tournament since winning a second Masters title, started the day four shots off the lead.
But after opening his third round with a birdie, his hopes of a fifth success in the event evaporated in a round which included six bogeys – four of them in a row from the turn.
He clawed one shot back at the par five 15th, but a 75 left him at one-under-par and 13 shots off the pace.
Fitzpatrick took a one-shot lead on 14-under-par over Norway's Kristoffer Reitan after both shot 64.
The Englishman, chasing a second PGA Tour victory after securing his card with a win at the Zurich Classic alongside brother and 2022 US Open champion Matt, who is a stroke behind McIlroy after a 69.
Alex Fitzpatrick made five birdies on his front nine, adding another on the 12th and two more either side of his only dropped shot on the 16th.
"I think having my brother around has been super helpful," he said.
"He’s been and done everything that I want to do in the game, whether that’s Ryder Cup and win majors.
"Having him, kind of, being around and me being there for all of that, I felt like I got a really good sense of what it takes and what the atmosphere is like."
American Cameron Young was two off the pace after a bogey at the last marred a round of 63, two ahead of Denmark’s Nicolai Hojgaard and overnight leader Sungjae Im.
At the Myrtle Beach Classic, Seamus Power shot his second consecutive 72 to slip one under par, good enough for a tie for 70th place.
American Mark Hubbard has the lead on 16 under par after a 64, which left him one stroke clear of England's Aaron Rai.
Five-time Major winner Brooks Koepka shot a 64 to sit five strokes off the pace.
