'I was nervous all day,' said Branshaw, who shot a 64 on Saturday to open a four-shot lead heading into the final round. 'I was nervous on the range. I was nervous everywhere. Everything's racing in your head and you keep thinking not to get ahead of yourself, and bam, I'm already there.'
Charles Raulerson and Aaron Baddeley tied for second place at minus 18. Charles Warren, Patrick Sheehan, D.A. Points and Doug Garwood were a shot behind them at 17-under.
Branshaw had a fairly steady round. He birdied the par-5 third, but gave that shot back with a bogey on No. 5.
'When the wind picked up today, we were playing an entirely different golf course,' Branshaw said, who earned $76,500 with the victory. 'I knew it was going to be tougher today. I thought if somebody shoots a 65 or 66 today, they deserve to win this thing.'
Branshaw got back into red figures with a birdie at the 10th. He gave that shot away with bogeys at the next two holes.
'I was hitting the ball crooked all day,' said Branshaw. 'After 12, I asked my caddie how we were doing and he said, 'Fine.' I was still pretty nervous, though.'
Branshaw would par out from there as he was never seriously challenged during the final round.
'After 16, my caddie told me that nobody was within four of me, so I'm thinking, 'Now I can really screw this up,'' said Branshaw. 'It wasn't until we got to 18 that I knew I could chip and two-putt and still win, that's when it finally hit me. I guess going to church this morning paid off.'
Raulerson and Baddeley each carded rounds of 68. Raulerson carded a single birdie on the front side, before posting three birdies and a bogey on the back nine.
Baddeley was making a run early in the round, with three front-nine birdies, but a pair of bogeys side-tracked him. He bogeyed the 11th and 14th, but was able to climb back into a second place tie with birdies at 16 and 18.
Final results from the Gila River Classic