Robert MacIntyre used a red-hot putter to birdie the last six holes and surge to a three-shot lead over Tommy Fleetwood in the US PGA Tour BMW Championship in Maryland on Thursday.
McIntyre delivered a masterclass on the rain-soaked greens at Caves Valley after an afternoon thunderstorm halted play for more than two hours.
"The last six holes is probably as good as I've ever putted in a stretch of holes, just so consistent," MacIntyre said after posting an eight-under par 62.
"When you get the eye on, it's free flowing and it's nice."
His late burst carried him past world No 1 Scottie Scheffler – who was in the clubhouse on four-under 66 and ended the day alone in third.
Fleetwood overtook him with a 33-foot birdie at 18 to cap a 65.
Two-under after his second bogey of the day on 12, MacIntyre poured in a 66-foot birdie putt at the par-three 13th to launch his scoring closing run.
He followed with a 40-footer at 14 and a 17-foot birdie at 15. He fired out of the rough to 12 feet at 16 and curled in that birdie putt, then drained a 22-footer at the tough par-three 17th.
MacIntyre capped his round with a five-foot birdie at 18.
The 29-year-old Scot's longest birdie streak on the PGA Tour – beating his previous of four straight – helped him match his career-low round on tour.
MacIntyre, who finished runner-up to JJ Spaun at the US Open in June, said he'd learned during the final-round rain delay at Oakmont and kept himself warmed up during Thursday's delay.
"It came at a tough time, but it gave the course a little more to us," he said. "The greens were really slick early on when they were dry. When I went back out, they felt a little bit slower, a little bit smoother."
Fleetwood had five birdies in an impressive bogey-free round, bouncing back after a late fade on Sunday saw him come up short in his latest bid for a first US tour title at the St. Jude Championship.
SCHEFFLER IN THE HUNT
Scheffler, whose four victories this season include major triumphs at the PGA Championship and the British Open, got off to a strong start with three birdies in the first four holes.
After back-to-back bogeys at nine and 10 he birdied three of his last four, drilling a 16-foot putt at 15 and a five-footer at 16 before draining a 26-foot birdie at the last.
Scheffler said the course was "significantly softer" after the storm delay.
"Golf course definitely got a bit easier but did a good job of taking advantage of the holes I had left," Scheffler said.
Fifty players are in the field this week and Scheffler, the leader in the playoff points race, is already assured of making it into the 30-player field for next week's Tour Championship in Atlanta.
Rory McIlroy, world No 2 and second in the playoff standings who opted to skip the first playoff event, carded an "awful" even par 70 that featured three bogeys and three birdies.
"Drove the ball terribly," the Northern Ireland star said.
It was a tough day for Justin Rose, who edged Spaun in a playoff for the St. Jude title in Memphis on Sunday.
Two-under through 10, he found the water at both 11 and 12 on the way to a bogey and double-bogey and carded a one-over 71.