Casas, who won $5,475, actually had a five-under card after 12 holes but bogeyed the par-4 13th for a 31-36 round and an 8-under 276 total, 13 strokes behind the winning 263 by Dyson, who beat Australian Kim Felton (68), Korean Charlie Wi (66) and John Kernohan of the US (64) by three shots.
Gerald Rosales slid to joint 27th with Robert Pactolerin, shooting a 69, after a 70, while Rodrigo Cuello likewise closed out with a 69 to finish in 33rd place at 228.
Dyson closed out the Asian PGA Tour season with another victory, his third, clinching the win with a 64 for a 21-under 263.
Felton, who led the second and third rounds, had a fine round of 68 but lost in the face of Dyson’s explosive windup.