Couples carded eight birdies and one bogey to finish on 11-under 129, one ahead of fellow American Joe Daley (64). Tom Lehman (67) was in third spot on 133.
Former US Masters champion Couples, the Presidents Cup skipper and one of Davis Love III's assistant captains at the 2012 Ryder Cup in Illinois in September, fired four birdies in the opening six holes.
He stalled briefly with a dropped shot on the 12th before bouncing back with another birdie on 13.
With Daley putting the pressure on, Couples ended his round in style with a hat-trick of birdies.