It's been a slow start to the new PGA tour for Australia's golfers, with none of the four Aussies in the field at the season-opening event in Napa breaking par on the first day.
Greg Chalmers, Matt Jones and Steve Allan are tied for 61st and at even par, with Aaron Baddeley a shot further back at one-over having started with an opening-round 73.
American Brendan Steele started his Safeway Open title defence with a 7-under 65 for a share of the lead with Tyler Duncan and Tom Hoge.
Lucas Glover, Chez Reavie, Emiliano Grillo and Jamie Lovemark were two shots back at 67.
Steele had an eagle, six birdies and a bogey. Last year at Silverado, he birdied the final three holes to overcome a four-shot deficit and beat Patton Kizzire by a stroke for his second PGA Tour title.
Duncan, making his first start as a PGA Tour member, also had six birdies, an eagle and a bogey.
Phil Mickelson, the 42-time PGA Tour winner beginning his 27th PGA Tour season, birdied the 18th from seven feet for a 69. The 47-year-old Mickelson, playing in his 91st PGA Tour event since his last title at the 2013 British Open, had five birdies and two bogeys.