Updated

La Quinta, CA (SportsNetwork.com) - Patrick Reed shot 9-under-par 63 on Thursday to grab a 1-stroke lead after the opening round of the Humana Challenge.

Reed, who earned his first PGA Tour win at the Wyndham Championship in August, went bogey-free at PGA West's Arnold Palmer Private, one of three courses in play during this pro-am event.

"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.

Ryan Palmer carded an 8-under 64 at Palmer Private to grab a share of second place. He stands alongside 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, a winner two weeks ago in Hawaii, fired a 7-under 65 at La Quinta. The world No. 6 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 final event before the 2013 FedExCup Playoffs, but the 23-year-old has failed to build on that momentum in the early part of the new wraparound season.

Thus far, Reed's 2013-14 campaign features a missed cut at the Frys.com Open, a withdrawal from the Shriners Hospitals for Children Open due to injury, a tie for 40th at the CIMB Classic and a tie for 16th at the Hyundai Tournament of Champions, his most recent event.

Reed broke 70 for the first time this season at the Tournament of Champions (in the third and fourth round) and he kept it going Thursday, firing a career-low round.

Starting from the 10th tee, Reed birdied two of his first four holes, then closed his opening nine with three straight birdies from the 16th to turn in 31.

Reed birdied two straight from the first and again carded back-to-back gains from the sixth, rolling in a 14-foot birdie putt at No. 7 to reach 9-under. He parred out from there to secure the first-round lead.

"I started out a little struggling with the driver, had some lefts in it, but luckily I missed it in the right spots," he said. "I was really confident with my irons, kept hitting greens and all of a sudden, 10-, 12-, 15-, 20-foot putts started going in."

NOTES: Johnson has now shot in the 60s in 30 of his last 37 rounds on the PGA Tour ... Defending champion Brian Gay is tied for 48th at 3-under 69 ... Boo Weekley withdrew during the first round due to a knee injury. Weekley was 2- over par through nine holes at PGA West's Nicklaus Private Course when he withdrew ... The format for the tournament is pro-am play for the first 54 holes. On Sunday, the low-70 pros and ties will play the final round on the Palmer Private Course at PGA West.