Bangladesh defeated Sri Lanka by five wickets in the last league match in Dhaka on Tuesday to go through to the Asia Cup final.
Tamim Iqbal (59) and Shakib Al Hasan (56) hit impressive half-centuries as Bangladesh achieved the rain revised target of 212 with 17 balls to spare in the day-night match.
Bangladesh will meet Pakistan in the final on Thursday.
Pakistan topped the league with nine points from three matches, followed by Bangladesh (8/3), India (8/3) and Sri Lanka (0/3).
The hosts made it to the final as they beat India in the league match.
Sri Lanka 232 in 49.5 overs; Bangladesh 212-5 in 37.1 overs