Camilo Villegas and David Toms share the lead at the Humana Challenge after both carding nine-under-par opening rounds of 63 on Thursday.
Colombian Villegas, playing the Nicklaus Course in La Quinta, California, holed four birdies on the front nine and five on the way in, including three in succession between 14 and 16.
He went bogey free for his first 18 holes of the PGA tournament - held across three courses - to hold a share of top spot on the leaderboard with Toms.
American Toms opened his challenge on the La Quinta Course, and also avoided a single bogey on day one.
The 45-year-old - a 13-time winner on the PGA Tour - made a solid start with four pars in succession, before producing an impressive run of four consecutive birdies between five and eight.
He holed five more birdies on the back nine, finishing in style with a three at the par-four 18th.
Four players sit one shot back from the joint leaders, tied for third at eight under.Americans Ted Potter Jr, Brandt Snedeker and Bob Estes, together with South Korean Bae Sang-Moon, all opened with eight-under 64s.
Australian Matthew Goggin shot the lowest round of the day on the Palmer Course, with a seven-under 65 earning him a share of seventh place.
While scoring was generally low in the third event of the PGA season, several big names did struggle.
Phil Mickelson, a four-time major champion, could only manage a two-over 74.At tied 134th, the American will need a much-improved performance during Friday's second round if he is to have any hope of making the half-way cut.
South African Trevor Immelman - the 2008 US Masters champion - fared even worse, stumbling to a four-over 76.