PALM SPRINGS, January 17, 2014 (AFP) - "I felt like there were some things I could have improved on, but at the same time whenever you tap in for par on the last hole and shoot 63, you're pretty happy," said Reed.
The 23-year-old Reed has struggled on the Tour since claiming his first victory at the Wyndham Championship in August.
His sizzling 63 Thursday came on the PGA West's Arnold Palmer Private course, one of three courses the competitors are playing in the pro-am event at La Quinta, 41 kilometres (25 miles) southeast of Palm Springs.
This week's Humana Challenge lacks the star power of most USPGA Tour events as just five of the top 30 players in the world are entered.
Rory McIlroy, Henrik Stenson, Justin Rose and Phil Mickelson are among the notable players not participating this week, with the Abu Dhabi Golf Championship scheduled to run at the same time.
Tiger Woods is expected to begin his 2014 by playing in next week's Farmers Insurance Open in San Diego, followed by the Dubai Desert Classic.
Ryan Palmer shot an eight-under 64 at Palmer Private to grab a share of second place Thursday. He is tied with Charley Hoffman, Daniel Summerhays and Justin Hicks.
Hoffman played La Quinta Country Club, while Summerhays and Hicks played PGA West's Jack Nicklaus Private Course.
Zach Johnson fired a seven-under 65 at La Quinta. Johnson won two weeks ago in Hawaii.
The world number six is tied for sixth place with 2010 champion Bill Haas, Hudson Swafford, Russell Knox, Charlie Wi, Matt Every and Brendon Todd.
Reed's win at the Wyndham Championship came in the last tournament before the 2013 FedExCup playoffs. He failed to build on that momentum in the early part of the 2013-14 season.
So far the American has missed the cut at the Frys.com Open, withdrew from the Shriners Hospitals Children Open due to injury, tied for 40th at the CIMB Classic and a tied for 16th at the Hyundai Tournament of Champions.
Reed broke 70 for the first time this season at the Tournament of Champions, and he kept it going Thursday, firing a career-low round.
Reed, who started from the 10th tee, birdied two of his first four holes, then closed his opening nine with three straight birdies. He made the turn with a 31.
Reed birdied two straight from the first and again posted back-to-back birdies from the sixth, rolling in a 14-foot birdie putt at number seven to reach nine-under. He parred out from there to claim the opening round lead.