LaBelle established a new tournament scoring record by finishing four rounds at 27-under-par 261, winning by two shots over Australian Nick Flanagan.
'It hasn't sunk in yet,' said LaBelle. 'There is a lot of good competition out here. All of these guys can win, so to be the one to do it is great.'
Flanagan -- one of three players who set a 54-hole tournament record to share the lead overnight -- closed with a 5-under 67 to end at 25-under-par 263.
Justin Bolli shot a 66 and Ken Duke a 67 to share third place at minus-24 at Highland Springs Country Club.
The last three Nationwide Tour events all ended in a playoff. LaBelle made sure it wasn't four in a row by hitting 13-of-14 fairways and 17-of-18 greens in regulation Sunday. He opened his round with three consecutive birdies and built a four-shot lead at one point.
The end result was LaBelle's third bogey-free round of the week and a $100,080 check for the win.
'It was not as easy as it looked out there,' he contested. 'I had butterflies from the moment I got to the putting green. I had to gather my emotions out there.'
LaBelle was able to gather his emotions long enough to post the second-lowest winning score in relation to par in Nationwide Tour history, behind only Daniel Chopra's 30-under total at the Henrico County Open in 2004.
His 27-under 261 total bested the previous tournament record of 25 under established by Brad Ott two years ago.
'I did what I've done all week and gave myself a lot of opportunities,' said LaBelle, whose only bogey of the tournament came during the third round at the par-four seventh. 'I played great all week.'
Boo Weekley, who shared the third round lead with Flanagan and former U.S. Amateur champion Jeff Quinney, shot a 69 and finished alone in fifth place at 23 under.
Quinney stumbled all the way to a share of 10th following a final-round 73.