Brent Schwarzrock fired an eight-under-par 64 to take a two-shot lead after the first round of the $4 million Pebble Beach National Pro-Am on Thursday.
Schwarzrock came home in a sizzling 28 shots, with six birdies and an eagle in his final eight holes, to move two strokes ahead of Matt Gogel and US PGA Tour rookie Pat Perez.
John Rollins, Jerry Smith, New Zealand's Phil Tataurangi and Jesper Parnevik of Sweden were in joint fourth place on 67, one ahead of Pete Jordan, Lee Janzen, Matt Kuchar and Paul Claxton.
World number one and tournament favourite Tiger Woods began his campaign with a two-under-par 70.
Lower back problems restricted Schwarzrock to just 20 events last season, with his best performance an eighth-place finish in his last appearance, at the Air Canada Championship.
But the 29-year-old from Orlando, Florida showed no sign of any back problems en route to his eight-under-par opening round at the Pebble Beach Golf Links, one of three courses being used this week.
He started his round on the 10th hole and made the turn in an even-par 36. Schwarzrock then eagled the second hole (his 11th) before recording birdies on six of his next seven holes, including the last four.
"I want to pick up tomorrow where I left off today," said Schwarzrock, who regained his tour card by finishing 18th at the 2001 Tour Qualifying School.
Gogel has made a habit of leading this event in previous years and he was at it again with a round that featured eight birdies and two bogeys.
Perez, making only his fourth tour appearance, had seven birdies and one bogey in his round at Poppy Hills.
The cold temperatures did not seem to bother most of the field as scores were generally low, even though play was halted because of frost for about 45 minutes.
Woods, who has been battling the flu, finished his round with a bogey at the 18th at Poppy Hills.
But Woods, who has never before broken 70 at Poppy Hills, was pleased with his first round effort.
Ireland's Richie Coughlan finished on 74 (two over), two shots better than defending champion Davis Love.
LEADING FIRST-ROUND SCORES
(US unless stated): 64 - B Schwarzrock; 66 - M Gogel, P Perez; 67 - J Parnevik (Swe), J Rollins, J Smith, P Tataurangi; 68 - P Claxton, L Janzen, P Jordan, M Kuchar; 69 - O Browne, F Couples, B Faxon, D Forsman, R Freeman, M Goggin, D Hart, A Magee, S Micheel, R Sabbatini (Rsa), V Singh (Fij), C Stadler, D Sutherland, K Sutherland; 70 - S Allan (Aus), J Byrd, K Clearwater, J Delsing, M Hulbert, K Jones, I Leggatt, S McCarron, J M Olazabal (Spa), R Pampling, C Perks, T Petrovic, L Porter, P Price, B Quigley, J Quinney, F Wadsworth, Tiger Woods.
