Piercy rolled in 12 birdies with two bogeys en route to a course record at the Silverado Resort in Napa, California.
"Oh man, I think I made more feet of putts than I did all last season," the American said. "We've been working on the putter a lot and trying to get some things figured out. Today was a good start off to the season, a good start to give me some confidence with the putter."
Piercy said it was the putter that let him down as he missed the Tour Championship – the finale of the 2015-16 season in September, as well as the Ryder Cup.
"I just missed getting to the Tour Championship, I ended up missing it by four strokes is what it comes down to," Piercy said. "Being 150th on the stats last year in putting I think we can figure out where it came from."
He's hoping to continue his success on the greens and add to his three US PGA Tour titles, the last of which came at the 2015 Barbasol Championship.
