The 25-year-old district sales manager won season 38 of the CBS reality competition on Wednesday night -- making him $1 million richer. ET spoke with Underwood right after the show, where he admitted he was "totally still in shock," but had an idea of how he was going to spend his winnings.
"I just got married a few weeks ago, so I've always had a dream to take a little time and travel and actually get a sail boat and live on that with my wife. It's kind of a crazy dream, but so is winning Survivor, so the sky's the limit," he said. "I'll definitely put some to savings because I want to have a family someday, so I'll have some money in the bank. But it's such an incredible opportunity and I'm really just really happy. I'm just really happy."
Underwood -- who said his wife was in tears in the audience when host Jeff Probst named him the winner -- is already working with a financial advisor. He joked she's going to have to keep him in check during his upcoming trip to Las Vegas.
"I'm going to Vegas this weekend with some of the other contestants, so I'm going to have to really curb the gambling," he cracked. "I've got a good person back home who is our financial advisor, so she's going to make sure I don't spend much."
The South Carolina native won Survivor: Edge of Extinction in a shocking twist, after he won his way back into the competition following weeks on Exile Island. With just days left before final tribal, he knew he was going to have to make a big move to win over the jury -- so he won Immunity, gave it up, and then challenged competitor Rick Devens to a fire-making competition. Underwood -- who spent just 13 days total in the game -- came out on top and ended up winning.
"That was the only way to win. It was really aggressive move in a season where there were so many aggressive players," he told ET, as runner-up Gavin Whitson told ET that he's not to thrilled about the season's twist. "It was the only that could happen to merit any respect from the jury, and I knew that going into it."
"If I didn't win that challenge, I was going to lose the game. If I didn't win that challenge and then take off the necklace, I was also going to lose the game. So, it was the only path," Underwood insisted.
Survivor returns to CBS this fall. See more on the series in the video below.