Snedeker, who was at 8-under 134, felt he was at an advantage because he goes to Pebble Beach for the final two rounds.
And there's one other edge for his psyche Tiger Woods isn't playing, and defending champion Phil Mickelson is six shots behind.
Snedeker has played so well this year that he is leading the FedEx Cup standings without having won. He was runner-up the last two weeks four shots behind Woods at Torrey Pines, and then four shots behind Mickelson in the Phoenix Open.
"Keep running into guys who are or who are going to be in the Hall of Fame," Snedeker said at the start of the week.
Mickelson, going after a record-tying fifth win in the event, was easing his way into contention until he made three bogeys in a four-hole stretch along the ocean at Spyglass Hill for a 71.
Snedeker sees the upside of his two second-place finishes: At least he's giving himself a chance.
"That's how you win out here," he said. "You keep putting yourself in position, and the more times you do, the more success you're going to have."
Bernhard Langer and Tom Pernice Jr. each shot 6-under 66 to tie for the first-round lead at the Allianz Championship at Boca Raton, Fla.
Langer, who holed out a bunker shot to win here in a playoff in 2010, birdied three of the last four holes.
Pernice was even through eight holes, but played the next six holes in six-under.
Pebble Beach National Pro-Am
Ted Potter Jr. -8
Brandt Snedeker -8
Fredrik Jacobson -7
John Merrick -7
Hunter Mahan -7
Patrick Reed -7
Mike Weir -2
Phil Mickelson -2
Daniel Summerhays +5