Steele's only previous victory had come at the 2011 Valero Texas Open and there were doubts whether he would add to his collection, having missed numerous opportunities.
The 33-year-old led the tournament in Napa last year going into the final round but five bogeys in the last seven holes ended his chances of lifting the title.
He has managed to redeem himself this time round with a sensational seven-under-par 65 enough to clinch the trophy by one shot on -18 from compatriot Patton Kizzire.
Speaking on the victory, Steele admits being able to get this second PGA Tour win is a big weight off his shoulders with the thoughts of never winning again crossing his mind on several occasions.
"I'd be lying if I said that maybe I was only going to win once on TOUR," he told pgatour.com. "I felt like my game was really good and I put myself in position a lot but didn't really execute coming down the stretch.
"I thought maybe I'm destined to just have that one win and play a long career out here but not necessarily keep winning, so this one definitely feels really good."
England's Paul Casey produced another solid performance as he claimed his fourth successive top-four finish without victory, finishing tied-third on -16 alongside Americans Michael Kim, Johnson Wagner and Scott Piercy.
Kevin Na was along in seventh on -15 whilst multiple major winner Phil Mickelson was in a group of five players that finished four strokes off the pace.