Patrick Reed furthered his lead at the Humana Challenge after matching his nine-under-par opening day score in the second round in California.

The overnight leader now has a two-shot advantage at the halfway stage of the competition formerly known as the Bob Hope Classic, which is being played across three different courses, after carding another 63.

Unlike day one, where the American recorded a bogey-free round at the PGA West resort's Palmer course, Reed did make his first blemish of the tournament on La Quinta.

But dropping a shot at the second came after he had birdied the first, and his charge began when he eagled the par-five fifth either side of birdies at the fourth and sixth.

Five more birdies after the turn followed as Reed moved onto 18-under-par overall.

"When you go over to La Quinta, the fairways are much more narrow than they are here, so you're really focusing on small targets," Reed told the official PGA Tour website.

"I just got off to a good start hitting it, so I built confidence through the first two holes."

The 23-year-old is two shots ahead of compatriot Brendon Todd, who emulated Reed's unblemished nine-under-par score at the Palmer course.

Todd, however, needed a birdie at the last to remain hot on the heels of the leader.

He began with five birdies in his opening seven holes although his charge stagnated slightly and he looked set to be three shots adrift of Reed until carding four on the par-five 18th.

Ryan Palmer currently sits third on 15-under-par overall after a round of 65 on La Quinta, while American compatriot Charley Hoffman is a shot further back.

Bill Haas and James Driscoll are in a tie for fifth on 13-under-par, Charlie Beljan is a shot back, and 1997 Open champion Justin Leonard and 2007 Masters winner Zach Johnson are two of eight players in a tie for eighth.

Keegan Bradley is two shots further adrift of that group on nine under par overall, but the 27-year-old provided the highlight of the day with his first ever hole in one on the PGA Tour at the 180-yard, par-three third hole on the Nicklaus Course.