Al-Amin Hossain was the pick of the bowlers for Bangladesh as he took 2 wickets in his 10-over spell.
Captain Angelo Mathews held his nerve under pressure and led from the front with an unbeaten half-century as Sri Lanka registered a three-wicket win over Bangladesh.
Opener Anamul Haque struck one six and two fours in his 86-ball 49 knock.
Ajantha Mendis took two wickets in his 9 overs spell giving away 55 runs.
Shakib Al Hasan scored just 20 runs before being dismissed by Ashan Priyanjan.
Chaturanga de Silva scored 44 off 52 deliveries chasing Bangladesh's 205.