With the two-stroke triumph, Couples became the first seniors tour player ever to take three of his initial four events, firing a 21-under 195 on the Punta Espada course to smash Mark Wiebe's 1-year-old tournament record by seven strokes.
Couples also set the Punta Espada course record with his 62, beating Bernhard Langer's 64 from the final round of last year's event.
Corey Pavin, who led after 36 holes, shot a 66, good for second place at 19-under 197. Pavin fell off the pace when he bogeyed from a sand-like area covered in crushed shells at No. 14.
Nick Price carded a 71 after fading over the last six holes, falling into a tie for fourth place with Bernhard Langer (67) and Tom Pernice Jr. (67) at 13 under 203.