MIAMI, 6 Mar 2015 (AFP) - The 32-year-old from Kentucky tamed Doral's Blue Monster course by hitting 15 of 18 greens as he goes for his first title of the season.
"You get a lot of adrenaline and everything going in a round like this," Holmes said. "I am pretty sure it is pretty good right now."
Holmes, who shared second place at the Farmers Insurance Open in early February, started on the back nine.
He got off to a flying start with two birdies followed by an eagle on the par-five 12th.
He two-putted for a birdie on the 10th then drained a 35-foot birdie putt on the 11th. His approach at 12 landed a foot away from the cup for an eagle.
"We had a game plan," Holmes said. "I hit all my shots where I needed to.
"I made sure I tried to stay below the hole. I had a day where I made a lot of putts and I just didn't have that many bad swings."
Fellow American Ryan Moore was alone in second place after firing a six-under 66. Moore was tied for the lead with Holmes late in the round, but he found water off the tee at the 18th and that led to a closing double-bogey.
Rickie Fowler, former runner-up Dustin Johnson and France's Alexander Levy share third place at four-under. Henrik Stenson, of Sweden, and Brooks Koepka, of the US, were a further stroke back at three-under 69.
Former Masters champion Adam Scott, who is making his first PGA Tour start of the season, carded a two-under 70. The Australian was joined in eighth place by Jim Furyk, Charley Hoffman, Gary Woodland and Jamie Donaldson, who shared second place last year.
World number one Rory McIlroy bounced back from a tough opening nine holes to post a one-over 73. He is tied for 27th with 11 others, including Keegan Bradley, Matt Kuchar, Justin Rose, Sergio Garcia and Graeme McDowell.
Leading first-round scores here on Thursday in the World Golf Championships Cadillac Championship at Doral (USA unless noted, par-72):
62 - J.B. Holmes
66 - Ryan Moore
68 - Dustin Johnson, Alexander Levy (FRA), Rickie Fowler
69 - Brooks Koepka, Henrik Stenson (SWE)
70 - Adam Scott (AUS), Gary Woodland, Charley Hoffman, Jim Furyk, Jamie Donaldson (WAL)
71 - Shane Lowry (IRL), Jimmy Walker, Ryan Palmer, Patrick Reed, Bubba Watson, Lee Westwood (ENG), Martin Kaymer (GER), Charl Schwartzel (RSA), Louis Oosthuizen (RSA)
72 - Victor Dubuisson (FRA), Luke Donald (ENG), Brendon Todd, Billy Horschel, Robert Streb
73 - Matt Kuchar, Cameron Tringale, Justin Rose (ENG), Danny Willett (ENG), Keegan Bradley, Morgan Hoffmann, Graeme McDowell (NIR), Rory McIlroy (NIR), Marc Warren (SCO), Sergio García (ESP), John Senden (AUS), Alexander Norén (SWE)
74 - Danie Van Tonder (RSA), Geoff Ogilvy (AUS), Koumei Oda (JPN), Bernd Wiesberger (AUT), Russell Henley, Phil Mickelson, Bill Haas, Webb Simpson, David Lipsky, Ian Poulter (ENG), Kevin Na, Brandt Snedeker