In the second over itself, Sylhet lost their opener Mohammad Haris (six), bringing Tauheed to the crease.
Towheed and Shanto added 88 runs from 56 balls for the second wicket to lay the groundwork for the start in the final overs.
Shanto dismissed fast bowler Al-Amin after scoring his first half-century of the season. Zakir Hussain (10) and Thisara Perera (11) made modest contributions at one end while Tauheed attacked at the other.