The Mobile, Ala., native started the day five shots behind Chad Bounds, but pulled even with birdies at Nos. 8, 9 and 10.
Lightning stopped play after Bounds birdied the par-3 12th to take a one-shot lead. Players took cover and waited to hear if play would resume. Had it not, the tournament would have ended with the 36-hole scores, and Bounds would have been declared the winner.
"If they'd have called it, I wouldn't have thought of it as a fulfilling win," Bounds said. "I wanted to play all three rounds."
Fifteen minutes before the deadline set by American Junior Golf Association officials to call the tournament, players were cleared to return to the course.
Wyatt wasted little time in pulling ahead.
"I was hoping we'd get through and we'd finish," Wyatt said. "I went back out there and took a few swings to get loose. I was excited."
At the par-5 14th, Wyatt and Bounds found the fairway with their drives. Both decided to go for the narrow green guarded by a creek.
Wyatt's shot landed just short of the green, where he would get up and down for birdie. Bounds pulled his second shot left into the trees. From a tight lie on the dirt, his pitch shot rolled over the green and into the creek.
Bounds' bogey gave Wyatt his first lead of the day.
"I had to hit the club really good to get it there," Bounds said of his ill-fated second shot. "Bobby's a good player. I knew he'd make birdie. That was definitely the turning point."
Wyatt carried a two-shot lead into the par-4 18th. His tee shot found the deep fairway bunker on the left side, and he was forced to blast out well short of the green. Bounds hit his approach to 10 feet, but Wyatt's pitch from 84 yards skidded to a stop a foot from the hole.
The tap-in gave Wyatt his first AJGA win.
He said he struggled with a bad swing during a first-round 72 and for much of his second-round 68. He finally flushed it on the driving range before his round Thursday to finish with a round only bested by Bounds' first-round 64.
"That was unbelievable," said Jay Vandeventer, who played in the final group with Bounds and Wyatt and finished third.
"I've played a lot of events with Bobby. He's always been a great putter."
There would be no similar comeback in the girls division. Orlando's Victoria Kiser ran away with her second AJGA title in two weeks, shooting a final-round 73 to win by 13 shots.
"My goal was to keep hitting fairways and greens," Kiser said. "I left a lot of shots out there. But overall, my game feels solid."
Reach Stephen Fastenau at (706) 863-6165 ext. 116 or firstname.lastname@example.org.