Mike Grob used a Sunday 68 to take second place at 15-under-par 273. Brad Fritsch and Eugene Smith shared third place at 14-under-par 274.
Third-round leader Stephen Gangluff posted a 1-under 71 in the final round to tie for fifth place at minus-13. He was joined there by John Mallinger, Iain Steel and Jon Turcott.
Anderson, who lost in a playoff to Matt Daniel at the 2002 Telus Edmonton Open, is the first Canadian to win on tour all season. He also has dropped some 35 pounds to get into better shape to improve his game.
'I am a pretty happy guy right now,' said Anderson. 'It's been a lot of hard work, frustration and dedication, and I've had the support of so many people along the way. This is for all of them as well.'
Anderson was keeping pace with Gangluff and the big turning point for the Canadian came at the par-5 seventh. His second shot came to rest under the lip of a bunker and he was forced to play backwards.
He managed to save par and then made his move on the inward nine. Anderson moved into a share of the lead with Casey Martin and Grob before he birdied the 15th to move one-shot clear.
Anderson then closed with back-to-back birdies from the 17th on Del Rio Country Club to seal his first tour win.
'I wasn't willing to let this one get away from me,' Anderson said. 'I can't lie, there hasn't been a month that's gone by where I haven't thought about that playoff loss. I still think, 'What if?' Now I don't have to think about it anymore. When I hit that shot on 17, I knew it was over.'
Martin could not sustain his momentum down the stretch. He closed with a 3-under 69 to share ninth place at 12-under-par 276 with Steve Schneiter, Brien Davis and Andrew Barnes.