After a procession of wickets, Tanzim Hasan Shakib and skipper Mashrafe bin Mortaza shared a 42-ball 48 partnership to take Sylhet closer to 100.
Mashrafe hit a one-ball 21 while Tanzim hit a career-best 41 off 36 balls, studded with five fours and two sixes, to entertain the thousands of Sylhet supporters in the stands.
Afghan fast bowler Azmatullah Omarzai set the pace of the innings with a spell of his opening three overs, where he dismissed Tom Moores (two), Towhid Hriday (0) and Mushfiqur Rahim (0) and conceded just three runs.