Multiple major winners Jordan Spieth and Zach Johnson each fired a seven-under par 63 Thursday to share the lead after the opening round of the US PGA Travelers Championship.
Johnson ran off six birdies in a row from the 11th through 16th holes before his lone bogey of the day at 17 snapped the American's dream streak.
Defending champion Spieth blasted out of a bunker 31 feet for eagle at the par-five sixth, evoking memories of the bunker hole-out the US star hit last year in a playoff to win the event at TPC River Highlands in Cromwell, Connecticut.
"It's good to see a good score," said Spieth. "It's round one. Just glad. The first rounds have been kind of detrimental to me, so it's nice to be in the thick of things."
Four-time major winner Rory McIlroy would have shared the lead if not for a closing bogey, missing the green on his approach at the 18th for stand on 64 with Americans Peter Malnati and Brian Harman.
"I played really well today," said McIlroy. "I feel like the work that I did over the weekend sort of started to pay off already. It was nice to see the shots I was playing right there. Being able to work the ball both ways was something."
Johnson, the 2007 Masters and 2015 British Open champion, made spectacular back-to-back birdies, sinking a 32-foot putt at the fourth and holing out from 73 feet at the par-three fifth.
But his real birdie binge began at the par-three 11th with an 18-foot putt. He sank a 15-footer at 12 and reached the green in two and two-putted to birdie the par-five 13th.
After four-foot birdie putts at 14 and 15, Johnson holed a 15-footer at the par-three 16th but took a three-putt bogey at 17 then closed with a tap-in par at 18 after his 109-yard third shot stopped inches from the cup.
Reigning British Open champion Spieth, the 2015 Masters and US Open winner, birdied the third and fifth ahead of his sensational sand shot at six.
He sank short birdie putts at 11, 13 and 14 but found water off the 15th tee and made bogey, but answered with a 20-foot birdie putt at 16.
McIlroy birdied four of the first six holes, his 11-foot birdie putt at the first his longest putt in the run, and ran off three birdies in a row starting at the 13th to signal his return to form after missing the cut at last week's US Open.