LAS VEGAS, October 18, 2013 (AFP) - Henry, who teed off on the 10th hole at TPC Summerlin, rolled in a 50-foot eagle putt at the par-five ninth to cap his round.
"It was one of those days," said Henry, a two-time PGA Tour winner whose effort included nine birdies.
"There wasn't much wind and the greens were pretty soft. It was nice to make that putt on the last hole to make lunch taste that much better."
On a day when birdies abounded, Henry had a one-stroke lead over Argentina's Andres Romero -- who had six birdies and two eagles in his 10-under 61.
"I was focused on my game and I was trying to do my job, and that's all," Romero said. "I wasn't paying attention to the leaderboard and the other guys."
Americans James Driscoll, Jonathan Byrd and Jeff Overton were tied for third on 63, one stroke in front of former US Open champion Webb Simpson.
"I played solid on the front nine," said Henry, who hit 17 of 18 greens in regulation and played his last six holes in six-under.
"I was just trying to get my feet wet and shoot a couple under par."
Henry is coming off a 16th-place finish at last week's Frys.com Open, which marked the official start of the US PGA Tour's 2013-2014 season.
Six tournaments are scheduled before January, offering FedEx Cup playoff points and a coveted Masters berth to the winner.
"With the changes (to the schedule), I thought it was important to get myself off to a good start," Henry said.
Byrd, who won the 2010 edition of this event with the first hole-in-one in PGA Tour playoff history, now finds himself trying to regain full playing privileges after wrist surgery late in 2012 sidelined him until March.
He made five cuts in 16 starts in 2013 and is trying to use the extra time provided by a major medical extension to match the 125th finisher on last season's money list and secure his card.
"I'll be happy when I get the major medical past me, because then I can really focus on the season," Byrd said.
Leading first-round scores on Thursday in the $6 million US PGA Shriners' Hospitals Open (USA unless noted, par-71):
60 - JJ Henry
61 - Andres Romero (ARG)
63 - James Driscoll, Jonathan Byrd, Jeff Overton
64 - Webb Simpson
65 - Stephen Ames (CAN), John Senden (AUS), Bryce Molder, Scott Brown, Heath Slocum, Chesson Hadley
66 - Ricky Barnes, Sean O'Hair, Cameron Tringale, Ryan Palmer, Will Claxton, Charley Hoffman, Daniel Summerhays
67 - Freddie Jacobson (SWE), Troy Matteson, Charles Howell, Derek Ernst, Charlie Beljan, Jason Bohn, Greg Chalmers (AUS), Russell Knox (SCO), Ryo Ishikawa (JPN), Edward Loar, Brendan Steele, Kyle Stanley, Vijay Singh (FIJ), Morgan Hoffmann, Jose Coceres (ARG), Brice Garnett, Brendon Todd