It was the 33-year-old’s first victory since the 2011 Valero Texas Open.

The two-time PGA Tour winner started the final round at the rain-soaked Silverado Country Club in Napa, California, four shots adrift of fellow countryman Patton Kizzire.

Steele, however, gradually chipped away at the lead with four birdies through his first eight holes. He added a fifth birdie at the par-4 10th before suffering a setback with a bogey at the 12th hole, which left him seemingly out of contention.

But a two-putt birdie at the par-5 16th hole kick-started his run at the title. He rolled in another birdie from 18 feet at the par-4 17th and then got up-and-down from 60 metres short of the 18th green for a closing birdie and a final round of 65 to set the clubhouse mark at 18 under.

Playing two groups in front of Kizzire, Steele then waited nervously to see whether Kizzire would catch him.

Kizzire, who is yet to win on the PGA Tour, made a terrific 15-foot par-saver at the 16th after mis-hitting his tee shot left and being forced to chip back to the fairway. He made another up-and-down from short of the 17th green, which left him needing to birdie the par-5 18th hole to force a play-off. But another errant drive left him in the rough and forced him to layup well short of the putting surface. His approach from 143 yards then missed the green to the right and he was unable to chip-in for a score-equalling birdie.

FINAL LEADERBOARD

"I thought that was it for me. I thought I would have to do something special. Last year, I tried not to make mistakes,” said Steele, who led this event into the final round last year but faded over the closing round.

"This is a little bit of redemption from last year. It's nice to close it off this way.

"You don't often get that chance in life to really redeem yourself in the same way at the same place, and to basically do just the opposite.”

Patton Kizzire and his caddie struggle to keep dry during the rain-interrupted final round. PHOTO: Ezra Shaw/Getty Images.

For Kizzire, this was his fifth top-10 in 2016 and it must be only a matter of time before he gets his hands on a trophy.

The same can be said for England’s Paul Casey, who shared third place at 16 under with Americans Michael Kim, Scott Piercy and Johnson Wagner.

Casey has now finished in the top-four in each of his last four PGA Tour starts dating back to the start of September. The 39-year-old is a cumulative 58-under-par from those four tournaments, with 15 of the 16 rounds being at par or better.

Queensland pair John Senden and Cameron Smith, as well as PGA Tour rookie Brett Drewitt, from NSW, were the best of the Australian contingent finishing tied for 35th at eight under.