The Nelsons' eagle-par-birdie finish gave them a 24-under 120 in the scramble format at ChampionsGate Resort, holding off a strong charge from Bob and Kevin Tway, who closed with a 59. The Tways were the runner-up for the second straight year.
Mark and Shaun O'Meara (62) finished third, one shot better than Curtis and Thomas Strange and Raymond and Robert Floyd.
Nelson, a three-time major champion, also won the Father-Son Challenge five years ago with Drew, his oldest son. He joined Floyd as the only players to win this tournament with different sons. Floyd won three times with Raymond Jr. and twice with Robert.
Josh Nelson, an entrepreneur from Atlanta who plays off a plus-2 handicap, did most of the work Saturday. In the final round, it was dad's turn to carry the load. Larry Nelson hit a 2-iron hybrid to 5 feet at the difficult 220-yard 14th for birdie, and he hit the same club to 18 feet, making the putt for eagle on the 510-yard 16th.
"He just doesn't fold under pressure," Josh Nelson said. "I feel he rises to the occasion. That's why he's a three-time major champion."
Larry Nelson earned $200,000, more money than he made in 18 events on the Champions Tour this year. His son is an amateur who is not allowed to accept more than $750 in prize money.
The Tways had a great opportunity to make a move at No. 16 after Kevin, a freshman at Oklahoma State and former U.S. Junior Amateur champion, knocked his approach to 12 feet. Both narrowly missed the eagle putt. The son's eagle putt grazed the left edge of the cup, and Tway's putt powered around the right lip.
"I'll take a 59 every time," Bob Tway said. "We just dug ourselves too deep a hole yesterday. I think we were just trying too hard."
The Tways were 3 under through 12 holes of the two-day tournament, and played the final 24 holes in 19 under.
Bernhard and Stefan Langer, the two-time defending champions, shot 63 and tied for ninth at 17-under 127 in the 18-team field that features major champions and their sons.
Arnold Palmer and grandson Sam Saunders, a sophomore at Clemson, closed with a 64 and tied for sixth. It was their best finish in this tournament.