'I woke up at six this morning as bright eyed as a kid. I couldn't wait to get started,' said Willis, who picked up $85,500 for the win. 'It is nice to finally see the fruits of my labor, all of the work is starting to pay off.'
Brian Henninger carded a 3-under 69 Sunday, but his bogey on the 72nd hole cost him a playoff. He finished at 12-under-par 276 and was joined there by Mathew Goggin (70) and Kris Cox (68).
After a lengthy weather delay Friday, the second round was completed Saturday and the third round finished earlier Sunday.
Willis got off to a quick start with birdies on one and three, both par-5s, to move to minus-13. He put it in cruise control from there as he parred the next seven holes at Willow Creek Country Club.
The 31-year-old stumbled to a bogey at the par-3 11th. Willis bounced right back with an 8-foot birdie putt on the par-5 12th.
Willis made it two in a row as his 12-foot birdie putt on the par-4 13th found the bottom of the cup. He parred his next three holes, but trouble loomed. Willis tripped to a bogey on the par-5 17th to drop to minus-13 and a share of the lead with Henninger.
Henninger, playing right in front of Willis, stumbled to a bogey at the last to slip into a share of second place and cost himself a shot at forcing a playoff.
Willis, who watched Henninger make his mistake, calmly two-putted for par on the last to earn his first Nationwide Tour title. He also won once on the PGA Tour back in 2001.
'It was a stressful day from the get go,' said Willis. 'With five par-fives, anything could happen. When the putt went in on No. 13 it was the first show of emotion for me all day. But I never thought about winning until that last putt.'
Henninger tripped to a bogey on the first. He came back with birdies on three and four to move to 10 under.
The three-time winner on the Nationwide Tour picked up another birdie on the eighth. Henninger collected back-to-back birdies from the 12th to get to 13 under. After Willis bogeyed 17 to drop back alongside Henninger, the USC alum bogeyed the last to share second.
'My approach hit a sod seam and it bounced straight back,' said Henninger of his shot on 18 that took a bad bounce into a water hazard. 'It was the weirdest bounce I've ever had and the worst break I've ever had in my career.'
Cox started with a bogey on the second. He got the stroke back with a birdie on three. The 31-year-old birdied the seventh and eighth to get to 10 under. Around the turn, he collected birdies on 12 and 17 to tie for second.
Goggin posted a 2-under 70 thanks to two birdies and a bogey on each nine.
Dave Christensen and second-round leader Brendon De Jonge shared fifth place at nine-under-par 279. Greg Chalmers, Deane Pappas and Tim Wilkinson tied for seventh at 8-under-par 280. Bill Haas was one stroke further back at minus-7.