Batting first at the R. Premadasa Stadium in Colombo, Jaffna were bowled out for just 123 in 19.3 overs. Their innings never gained momentum after a strong start, with Kamil Mishara making 41, while Towhid Hridoy managed only 10 off 10 balls.
For Galle, Charith Asalanka and Eshan Malinga claimed three wickets apiece, while Tharindu Ratnayake took two.
Chasing 124, Galle reached 126 for 5 in just 15.5 overs, winning with 25 balls to spare. Thomas Rogers scored 34 off 27 balls, while Dinura Kalupahana added a quick 31 off 19.
Captain Dasun Shanaka then finished the chase in style, smashing an unbeaten 20 off just nine balls.
Bangladesh all-rounder Shakib Al Hasan played a key role with the ball, taking 2 for 15 from four overs. He struck twice in the Galle chase, removing Thomas Rogers and Dinura Kalupahana to keep Jaffna in the contest. With the bat, however, Shakib could manage only 9 off 13 balls.
Meanwhile, Nurul Hasan Sohan did not feature for Galle in the final.