The 52-year-old Durant won on the par-5 18th after closing with a birdie on the hole in regulation for a 9-under 63. After a double-bogey on the par-4 14th, Jimenez birdied the final four holes for a 67 to match Durant at 19-under 197 at TPC Twin Cities.
Jimenez birdied the 18th in the playoff before Durant rolled in the right-to-left winner.
Durant won for the second time on the 50-and-over tour and the first by himself after teaming with Billy Andrade to win the Legends of Golf last year. Durant won the last of his four PGA Tour titles at Walt Disney World in 2006.
He opened with a 70 and shot a 64 on Saturday to begin the final round four strokes behind leader Jimenez. Durant birdied Nos. 1-2, 4-5 and 7-8 in a front-nine 30 and added birdies on Nos. 10 and 12. He dropped a stroke on the par-3 13th and got it back with a birdie on the par-4 14th.
Jimenez shot 67-63 to take a one-stroke lead over Kevin Sutherland into the final round.
Two weeks ago at Carnoustie in the Senior British Open, Jimenez took a four-stroke lead into the final day only to shoot 75 and tie for third -- three strokes behind winner Paul Broadhurst.
Jimenez won in Mississippi in March for his third career PGA Tour Champions victory. The 52-year-old Spanish player has 15 regular European Tour victories, the last in the 2014 Spanish Open at a tour-record 50 years, 133 days.
Two-time winner Bernhard Langer had a 64 to tie for third with Sutherland (68) at 17 under. Langer has broken par in all 24 of his rounds in the event.
David Frost (66) and Monday qualifier Glen Day (68) followed at 16 under. Two-time defending champion Kenny Perry had a 68 to tie for 37th at 7 under, and John Daly tied for 71st at 3 over after a 75.