His total ties the tournament scoring record set by Mike Heinen and Steve Alker in 2002.
Ken Duke shot a final-round 71 to finish alone in second place at 21-under-par 267. Russ Cochran (68) and Steve Allan (73) shared third place at 19-under-par 269.
The 29-year-old Wetterich jumped out to a quick start with an eagle at the first. He faltered with bogeys at the sixth and ninth, but had birdied the par-3 eighth to make the turn at 1-under.
On the back nine, Wetterich bogeyed the par-3 11th, but came right back with a birdie at the next. He capped his win with a birdie at the par-4 15th.
Wetterich claimed $85,500 with the victory. He entered the season with just $4,645 in career earnings on the Nationwide Tour.
Tom Carter finished alone in fifth place at 18-under-par 270, one stroke ahead of Brent Schwarzrock (66) and Wes Short (71).