Bangladesh, which scored 253 runs in the first innings, resumed the 2nd innings on Monday morning with their overnight total of 170 for 9 were bundled for 175 runs giving an easy winning target of 172 runs for the visitors.
Afghanistan with their first innings total 257 runs opened the 2nd innings and scored the match-winning 173 runs for 3 in 58.3 overs, riding on unbeaten fifties by Ibrahim Zadran (76) and Nasir Jamal (59).
For the 2nd string Bangladesh team, left-arm medium pacer Salauddin Sakil bagged two wickets while left-arm spinner Sunzamul Islam took one in the 2nd innings.
Qais Ahmad made the major damage to Bangladesh 2nd innings claiming 7 wickets for 62 runs and was adjudged man of the match.
Besides, Yamin Ahmadzai, Naveen-ul-Haq and Sharafuddin Ashraf picked up one wicket each for the visiting Afghanistan.
Both teams will lock horns in the 2nd and final 4-day match beginning on July 12 at Zahur Ahmed Chowdhury Stadium, Chattogram.