His fifty came off 102 balls which included four boundaries.
His fifty came off 104 balls which included five boundaries with a strike rate of 47.61.
Currently, Mushfiqur Rahim and Shuvagata Hom are batting on 41 and 9 respectively.
Bangladesh rebounded to finish on 242 for nine, with Imrul scoring 112.
Four players in the squad in the ongoing Test series against the West Indies here have been named in a strong Bangladesh A squad to tour the Caribbean next month.
Bangladesh made a long-awaited breakthrough in their ODI series against Zimbabwe by winning the fourth of five One-Day Internationals at Queens Sports Club on Friday.