David Mathis outshone a trio of Major champions to take a first-round lead after a scintillating start, which included a hole-in-one, at the Travelers Championship.
Attention beforehand had focused on last week's US Open winner Webb Simpson and reigning Masters and USPGA champions Bubba Watson and Keegan Bradley, playing together in an eye-catching group.
All three scored well on day one at TPC River Highlands in Cromwell, Connecticut, with Simpson and Watson shooting 66 and Bradley a two-under-par 68 to put themselves firmly in the hunt.
But none could match the efforts of Mathis, who missed the cut while Simpson was winning at San Francisco's Olympic Club but hit the ground running in spectacular style on Thursday.
Starting from the 10th, he followed an opening birdie with a hole-in-one at the 158-yard 11th before holing a 49-foot birdie putt at the next.
"It was an awesome start," he told the PGA Tour's official website, before delivering a modest assessment of his ace.
"It kind of bounced and stumbled right and went right in the hole."
Further birdies followed at 14 and 15 to take him to six under, where he would finish his round after dropped shots at 18 and eight were cancelled out at the third and ninth.
"I was hitting a lot of great shots, and I guess it felt like a lull compared to how I started," he added.
Sweden's Fredrik Jacobsen could have led the way but for a double-bogey five at the 16th, the only blemish on a card containing seven birdies.
He instead shares second place with American Will Claxton, who started birdie-eagle but saw a closing bogey cost him a share of the lead, and Australian Nathan Green, whose back nine contained five birdies and one bogey.
A shot further back, Simpson carded five birdies and just a solitary bogey, again at 16, while an eagle at the par-four 10th was the highlight of Watson's round.
"We were relaxed all day," Simpson said. "Bubba is my Presidents Cup partner. We always laugh together.
"And I've played a lot of golf with Keegan this year. He's a good friend. We had a lot of fun feeding off each other, and luckily, we all played well."
Watson added: "Any time you can play with those guys, it's fun.
"We learn from each other. We watch each other. We're making some jokes out there. We were having a good time."
The group at four under also contains Rocco Mediate, runner-up to Tiger Woods in the memorable US Open play-off of 2008, as well as South African Tim Clark and England's Gary Christian.
Ian Poulter joined Bradley on two under, one behind another Englishman in Brian Davis, while Ireland's Padraig Harrington followed up his fourth place at the US Open with an opening 69.
But Patrick Cantlay, in his first professional event after a stellar amateur career highlighted by a 60 on this course last year, struggled round in a five-over-par 75 after opening with back-to-back double bogeys.
Collated first round scores
(USA unless stated, par 70):
64 David Mathis
65 Nathan Green (Aus), Fredrik Jacobson (Swe), Will Claxton
66 Jerry Kelly, Gary Christian (Eng), Bubba Watson, Chez Reavie, Webb Simpson, Roland Thatcher, Tim Clark (Rsa), Kevin Kisner, Rocco Mediate, Tommy Gainey
67 Brian Davis (Eng), Charley Hoffman, Chris Di Marco, Greg Chalmers (Aus), Matt Kuchar, Aaron Baddeley (Aus), Stephen Gangluff, Brandt Jobe, Ken Duke, Roberto Castro
68 Patrick Sheehan, Seung-yul Noh (Kor), Garth Mulroy (Rsa), Billy Mayfair, Brian Gay, Graham Delaet (Can), James Driscoll, Nick O'Hern (Aus), Derek Lamely, Kevin Streelman, Keegan Bradley, Robert Karlsson (Swe), John Rollins, Robert Allenby (Aus), Marc Leishman (Aus), Ian Poulter (Eng), Camilo Villegas (Col), Stuart Appleby (Aus)
69 Kris Blanks, Danny Lee (Nzl), Louis Oosthuizen (Rsa), J.J Killeen, Blake Adams, Mark Anderson, Harris English, Billy Hurley III, Jeff Maggert, Brendon Todd, Cameron Beckman, Johnson Wagner, Shane Bertsch, Cameron Tringale, Padraig Harrington (Irl)
70 Vaughn Taylor, Steven Bowditch (Aus), John Peterson, Heath Slocum, Jamie Lovemark, Sean O'Hair, Bo Van Pelt, Kyle Stanley, Lucas Glover, Brian Harman, William McGirt, Hunter Mahan, Charlie Wi (Kor), J.B. Holmes, John Huh (Kor), Russell Knox (Sco)
71 Bryce Molder, Chris Stroud, Rory Sabbatini (Rsa), Bart Bryant, Colt Knost, Vijay Singh (Fij), Arjun Atwal (Ind), Miguel Angel Carballo (Arg), Tim Petrovic, Billy Horschel, Daniel Summerhays, Troy Matteson, Y.E. Yang (Kor)
72 Bud Cauley, Chris Couch, Bryden Macpherson (Aus), John Mallinger, Kyung-Tae Kim (Kor), Francis Quinn, Chad Campbell, Steve Marino, Patrick Rodgers, Hunter Haas, Brendon De Jonge, Rodney Pampling (Aus), Tim Herron, John Merrick, Zach Johnson, Neal Lancaster, Sung Kang (Kor), Ricky Barnes, Mathew Goggin (Aus), Richard H. Lee, Ryan Moore
73 Bill Lunde, Gavin Coles (Aus), Charlie Beljan, Edward Loar, Alexandre Rocha (Bra), Kenny Perry, George McNeill, J J Henry, Mike Carbone ,. Notah Begay III, Jhonattan Vegas (Ven), Patrick Reed, D.J. Trahan
74 Jason Kokrak, Michael Bradley, Joe Ogilvie, Angel Cabrera (Arg), Steve Wheatcroft, Tom Pernice Jnr., Matt Bettencourt, James Hazen, Brendan Steele, Ryo Ishikawa (Jpn), Justin Leonard, Daniel Miernicki, Kyle Reifers, Ryuji Imada (Jpn)
75 Scott Dunlap, Ted Potter, Jr., Bobby Gates, Troy Kelly, Patrick Cantlay
76 Brad Faxon, Kevin Stadler, Kyle Thompson, Steve Flesch, Matthew Jones (Aus), Jason Bohn
77 Joey Snyder III, Ian Marshall, Tom Gillis
78 Daniel Chopra (Swe), Michael Thompson, Matt Mcquillan (Can), Michael Putnam
79 Sang-moon Bae (Kor), Kelly Kraft
82 Tommy Biershenk
83 Scott Brown