West Indies skittled out for 108, their second-lowest score on home soil, as Bangladesh spinners wreaked havoc, taking 8 wickets among them.
Keemo Paul was the only batter to cross the 20-run mark as West Indies lost wickets at regular intervals.
Off-spinner Mehidy Hasan Miraz led the rout with figures of four for 29 while left-arm slow bowler Nasum Ahmed claimed three for 19 as the home side’s batsmen once again appeared all at sea on a pitch that offered considerable assistance to the spinners.
Beaten by six wickets in the first match at the same venue on Sunday, West Indies tried to build a more stable platform after predictably being put in to bat by Bangladesh captain Tamim Iqbal.
However the dismissal of Kyle Mayers by the spin of Mosaddek Hossain after an opening stand of 27 in the 11th over triggered the slide which saw the hosts crashing to 86 for nine in the 31st over.
An unbeaten 25 by all-rounder Keemo Paul and a last-wicket stand of 22 with fellow-Guyanese Gudakesh Motie at least took the West Indies past the 100-run mark.
However, it leaves Motie and fellow frontline spinner Akeal Hosein with a huge challenge to match the success of their Bangladeshi counterparts and prevent their opponents from extending their ODI winning streak against the West Indies to 10 matches.