Phil Mickelson shot a 69 and was one of 12 players tied for 12th.
Past year at Silverado, he birdied the final three holes to overcome a four-shot deficit and beat Patton Kizzire by a stroke for his second PGA Tour title.
Duncan missed out on PGA Tour status via the Web.Com regular season but played his way to the "big time" with a good run through the Web.Com Tour finals and has made a dream start at this higher level despite a golf course which firmed as the afternoon progressed.
Lucas Glover, Chez Reavie, Emiliano Grillo and Jamie Lovemark were two shots back at 67.
Among the standout shots was a deft chip from a bunker on the par-five 16th which led to an easy two-foot par for a birdie. "I hit a lot of good shots, rolled and a lot of good putts and was able to watch Chesson go insane". Finau then got in at 13 under with a closing birdie, but Steele finished par-birdie to post at 15 under.
Steele had six birdies and a bogey in a 67. That was a strong 3-under 69 on Sunday, but that double bogey may haunt him for a bit.More news: EPA to withdraw from Obama-era Clean Power Plan
"I'm proud of the way I played today". "I knew the weather was going to be windy and it seems Sunday is always the hardest day on the PGA Tour for whatever reason".
The 2017-18 PGA Tour season-opening event proved be quite fruitful for the 47-year-old as he finally delivered on the course when it mattered.
The last PGA Tour title won by Mickelson was back in 2013, the same year he won both the US Open and The Open Championship. A bogey-free 7-under 65 put Hatton, a second-round co-leader, at 18-under 198 and in a commanding position to defend the title he won by four shots past year. I had a really good ball-striking day.
After a bogey on the second hole, Mickelson birdied five of his last six holes on the front nine to move to 11 under and within two shots of the lead.
The current leader Tyler Duncan was tied at the top after the first round but bogeyed on the second, third and fourth to sit at one under for the day after four second-round holes on the front nine. Hadley ended up parring 18 to shoot 73 and tie for third at 12 under. He nailed just about each one except for finishing in the top 10 at half of his PGA Tour events.