Russell Knox and Hunter Mahan have a share of the lead after day one of the Pebble Beach National Pro-Am.
The tournament, which is held across three different courses, pits professional players against amateurs over four days.
Scotsman Knox holed eight birdies and two bogeys at the Monterey Peninsula Country Club to give him a six-under-par round of 64.
Meanwhile, American Mahan recorded his six-under with a score of 66 at Pebble Beach.
The highest score on the third course, Spyglass Hill, was a five-under 67 by South Korea's Noh Seung-Yul.