The duo finished regulation tied at 13-under-par 275. Purdy put together a final-round, 1-under 71 while Tidland posted a 4-under-par 68 on Sunday.
Both golfers played 36 holes on Sunday as rain washed out Saturday's action. With the long hours on the course and the waning sunlight, the third playoff hole was to be the last with a Monday finish possible.
The two made their way to the par-5 18th, which is where the two would determine the champion no matter how often they needed to play it. On the third time around 18, both players found the fairway off the tee and laid up short of the green. Purdy played his third shot to two feet then Tidland knocked his approach to seven feet. Tidland's birdie try missed the hole on the right edge but Purdy sank his to win for the first time on the Nationwide Tour.
'Everybody wants to end it in regulation,' said Purdy, who pocketed $85,500 for the win. 'I've never had a longer day. Eight to eight and we're still here but this is huge for me. What a great way to spend Easter Sunday.'
'I hit a good putt, it just lost its speed at the hole,' said Tidland, the 1995 NCAA Champion. 'I thought I had the line there but I wouldn't trade this week for anything.'
On the first playoff hole, Tidland had a 12-foot birdie putt that could have won the title. That putt never fell into the cup and then Purdy missed a five-footer for birdie at the second extra hole that also would have ended the tournament.
'The first one that I missed was nerves. That was all me,' said Purdy. 'I thought for sure that Chris was going to make the last one but it was getting dark. I think that's why he missed it. I don't think he could read the break too well.'
Purdy needed help getting into the playoff. He holed a 15-foot birdie putt at the 72nd hole to reach 13-under par and Tidland helped keep Purdy's chances alive by missing a 12-foot birdie putt of his own at 18 some 30 minutes prior.
Vance Veazey (69), Tjaart van der Walt (70) and first and second-round leader Zach Johnson (72) shared third place at 12-under-par 276.
Mike Grob (68), Danny Ellis (70) and Bo Van Pelt (72) tied for sixth at minus-11. Lucas Glover (68), D.A. Points (68) and Bob Heintz (71) came in a joint ninth at 10-under-par 278.