His 7-pound, 10-ounce bag Sunday was barely enough to push Louisiana's Cliff Crochet into second place -- by just 2 ounces.
"I'm about to throw up right now," Williamson told an excited crowd at Wildwood Park as he stepped to the stage for the final weigh-in. "Let's put this thing on the scale and see what we got!"
When the dust had settled, Williamson's four-day total was 53 pounds, 6 ounces, to Crochet's 53 pounds, 4 ounces.
The 29-year-old Williamson, whose heavy bag Saturday gave him a 4-pound lead going into Sunday's 12-way final round, said winning the event so close to home is a lifelong dream come true.
"I had told my dad, I'd love to win the Classic, and I'd love to win Angler of the Year, but before that, I really wanted to win one at home," he said. "Today, we did it."
With skyrocketing temperatures, Williamson -- who has fished Thurmond Lake much of his life -- knew the bigger fish would be migrating to the lake's upper end, where cooler water could be found. He settled on one particular area because it was 5 degrees cooler than the rest of the reservoir.
Crochet, a rookie to the Elite series who was hoping for his first big win Sunday, was visibly disappointed to lose by such a slender margin. After weighing in an 11-pound, 11-ounce bag, he hoped it would be enough to secure the win. But it wasn't to be.
"That's the nature of the beast," said Crochet, who was still shaking minutes after the results had been decided. "I'm wrecked right now, but if you look at the big picture, I'm fishing against the best in the world and I'm loving it."
Finishing third was Terry Scroggins, of Palatka, Fla., with 48 pounds, 9 ounces. Matt Reed, of Madisonville, Texas, moved up from 12th place Sunday to take fourth with 47 pounds, 13 ounces. Two-time Toyota Tundra Bassmaster Angler of the Year Gary Klein, of Weatherford, Texas, finished fifth with 43 pounds, 11 ounces.
Williamson had a huge following Sunday, including his sisters, who sang the national anthem, and many anglers he has faced in local competitions.
"You guys made me what I am today," he said, "and I thank you for it."
Though most of the pros acknowledged the lake was stingy this week, with changing weather patterns, heat and elusive baitfish, the competitors still landed a total of 1,106 bass that weighed 2,120 pounds, 2 ounces.