Lunde, the overnight leader, lost a two-shot lead thanks to consecutive bogeys at the 15th and 16th holes, but his birdie at the 72nd hole gave him the win.
Lunde only managed a 2-over 73 and finished the tournament at 5-under 279.
Not bad for a guy who left professional golf in 2006 out of frustration.
'Attitude is an amazing thing,' Lunde said. 'When you come out with a different outlook, things happen positively. It was never talent. It was whether I could stay positive out there.'
Dustin Bray, who has no status on the Nationwide Tour, shot a 2-under 69 to finish second at 4-under 280. Tommy Tolles (69), Skip Kendall (71) and Brendon de Jonge (73) shared third place at 3-under 281.
Lunde started off terribly with a double-bogey at the second, but got one stroke back thanks to a birdie at the par-5 fourth. He parred his next six, which was a great score at Ohio State's Scarlet Course.
Lunde bogeyed No. 11, but recovered that lost shot one hole later thanks to a birdie at the par-5 12th. Staying around even-par for the day was good and he found himself two clear with four to play.
De Jonge bogeyed 15 to fall two back, then bogeyed 18 to get into the clubhouse at minus-3. That meant the championship was down to Lunde and Bray, who already completed his final round.
Lunde found trouble. He bogeyed the 15th and 16th holes to lose his lead. He was tied with Bray at four-under and parred the par-3 17th to stay knotted in first.
Then Lunde drove into the rough at 18. He missed the green with his second, but was not in terrible shape. He was just off the fringe and therefore could not putt it.
Hardly mattered for Lunde. The ball rolled right into the cup for the win.
'It was pretty cool to finish off that way,' said Lunde, who pocketed $135,000 for the win.