Nelson fired a final round 4-under-par 68 to best Bill Brask and Jim Thorpe by one shot at 13-under-par. Brask, who lead after the first round, and Thorpe each carded 2-under-par 70s on Sunday.
Defending champion Tom Watson finished with Gil Morgan in a tie for fourth at 11-under. Watson and Morgan posted final rounds of 67 and 71, respectively. Last year, Watson shot a Sunday 62 to win his first, and thus far, only Senior Tour event at the Bent Tree Country Club.
This is Nelson's third win in his last four starts. The lone exception was a runner-up finish at last week's Kroger Classic.
'I didn't hit the ball as well this week as I have the last three to four weeks,' said Nelson. 'I think 1979 on the PGA Tour was similar to this year. It seemed like every week I had a chance to win that year.'
With his $210,000 first-place check, Nelson surpasses Bruce Fleisher on the 2000 money list. Nelson has earned $2,271,555 this season, $100,749 more than Fleisher, who tied Hale Irwin for 11th this week.