The win was Hietala's second on the Nationwide Tour. His other victory came at the 2005 Louisiana Open.
Hietala posted a 2-under 69 to match Branshaw, who tallied four back-nine bogeys en route to a 2-over 73. The pair finished regulation at 19-under 265 and headed back to No. 18 for the extra session.
At the first playoff hole, the pair was on opposite sides of the fairway, but Hietala was in a divot. Branshaw played first and clobbered his approach over the green, Hietala mishit a low bullet into the right fringe.
Branshaw had a terrible lie, but pitched four feet past the hole. Hietala ran his third to a foot and tapped in for the par.
Branshaw pulled his four-footer, giving Hietala his first win in almost three years.
'I'm speechless,' said Hietala. 'God, what a struggle. What a feeling.'
Branshaw led Hietala by four shots at the start of the final round. Branshaw only made two birdies on the front versus three from Hietala, so at the turn, the margin was three.
Hietala, playing one group ahead of Branshaw, drained a six-footer for birdie at the par-5 10th. Branshaw drove into a bush and could not save par, cutting the lead to a single stroke.
Hietala bogeyed both 11 and 12. Branshaw three-putted both holes for bogey, his third in a row, but the margin was still one shot. Hietala bogeyed No. 14 and Branshaw had a two-shot lead with three to play.
At the par-5 17th, Hietala drove into the right rough up against a hill. He choked down on his club and somehow reached the green in two. Hietala, the second-round leader, two-putted for birdie.
Behind Hietala, Branshaw hit his tee ball into a greenside bunker at 16. He blasted out to eight feet, but missed the putt and dropped himself into a tie for the lead with Hietala at 19-under par.
Hietala hit a terrible second shot from the fairway at 18 right of the putting surface. He hit a flop-shot to three feet and converted the par save to get in at minus-19.
Branshaw had an eight-iron for his second shot at the par-5 17th, but pulled it long and left. His chip ran 10 feet past the stick and Branshaw failed to hole his birdie effort for the lead.
Branshaw found the right rough off the tee and got a free drop after his feet were on the cart path. His second came up about 45 feet short of the flagstick, giving him an unlikely birdie putt for the win.
A two-putt par and a playoff seemed like the best option for Branshaw, but a pair of three-putts on the back nine may have loomed his mind. He had a difficult ridge to negotiate and left his birdie putt for the win nine feet short.
Branshaw needed the putt and converted it to force the playoff, but the trophy ultimately went to Hietala.
'I didn't know he dropped three or four shots until I looked at the board on 16,' admitted Hietala. 'I knew that stretch of holes was playing tough. I played with Branshaw yesterday. He played great and hats off to his game this week.'