Joining him at the top on 11 under overall are Sweden's Ludvig Aberg (65) and overnight leader Thomas Detry, of Belgium who lost a few shots coming in at Pebble Beach for a 70.
Patrick Cantlay was poised to join them except for missing a 10-foot birdie putt on the 17th at Pebble Beach, and then hitting his tee shot on the 18th onto the rocks, forcing him to scramble for a hard-earned par and a 70. He was one shot behind.
The 80 players in the signature event's field are playing one round apiece at the Pebble Beach and Spyglass Hill courses to open the tournament.
They will proceed to Pebble Beach for the weekend rounds without a 36-hole cut as they compete for a $US20 million ($A30 million) purse in what is forecast to be heavy wind and rain.
The leading nine players going into the weekend all played at Pebble Beach on Friday, an advantage when the wind was down and the conditions were soft.
Also in action at Pebble Beach were the three Australians in the field.
Adam Scott's day started with a bang, carding an eagle on his second hole along with five birdies on his way to a five-under 67 and a share of 23rd place overall.
He is joined by Cam Davis, whose three birdies on his back nine left him three-under 69.
Jason Day (71) was a shot further back at four under overall in a tie for 34th.
At Spyglass Hill, Collin Morikawa had a 70 and was among those four shots behind the leaders.
Nick Dunlap, the US Amateur champion who turned pro after he won The American Express two weeks ago, continued to have a rough time.
He shot 74 at Spyglass Hill and was tied at the bottom of the leaderboard, six over after 36 holes.
