Spinner Mehidy Hasan and Bangladesh exploited "ideal conditions" to defeat the West Indies by six wickets in Sunday's rain-affected first one-day international.
Shoriful Islam's haul of 4-34, his best in ODIs, limited the West Indies to 149 for nine batting first in a fixture reduced to 41 overs-per-side before Mahmudullah's unbeaten 41 saw the visitors to the target with more than nine overs to spare.
After 2-0 losses in both the preceding test and T20 International series, Bangladesh's ninth consecutive ODI win over the West Indies puts the pressure on the home side going into the second match at the same venue on Wednesday.
Mehidy played his part in a disciplined bowling effort with three wickets.
Senior pace bowler Mustafizur Rahman set the tone for the match when he dismissed dangerous opener Shai Hope for a first-ball duck after Bangladesh captain Tamim Iqbal put the home side in to bat.
Mehidy's victims included West Indies captain Nicholas Pooran and earned him the man of the match award.
"This is a really good result for us because rain prevented us from practising properly for the last few days," said the spinner.
"These were ideal conditions for us. I just tried to bowl in the right areas and everything worked out well for us."
Shamarh Brooks top-scored with 33 for the hosts with the next best effort being an unbeaten 19 from Anderson Phillip in an unbroken last-wicket partnership of 39 with Jayden Seales (16 not out).
Shoriful went one better than Mustafizur in taking the wickets of Brandon King and Brooks in his opening over before adding the Guyanese pair of allrounder Romario Shepherd and spinner Gudakesh Motie.
However, the coveted fifth wicket of the innings proved elusive as Bangladesh's fielders dropped three catches to extend the last-wicket resistance of Phillip and Seales.
With the sun coming out to ease the batting conditions, Bangladesh were always favoured to overhaul the target and 37 from Najmul Hossain together with 33 by Tamim at the top of the order set them on their way.
Tamim was run out and Najmul because the first wicket of ODI debutant Motie, although those were mere stutters on the journey to victory as wicketkeeper-batsman Nurul Hasan joined Mahmudullah in an unbroken fifth-wicket stand of 40 to see their side to victory.
"In hindsight our total today obviously wasn't enough but it was difficult to get more batting first on that track," was Pooran's frank assessment of the conditions at the start of the match.
"Conditions improved later on but having said that, we should have pushed harder for more success at the start of their innings to give ourselves a fighting chance."
WEST INDIES: Shai Hope, Brandon King, Kyle Mayers, Shamarh Brooks, Nicholas Pooran (capt & wk), Rovman Powell, Romario Shepherd, Akeal Hosein, Anderson Phillip, Jayden Seales, Gudakesh Motie
BANGLADESH: Tamim Iqbal (capt), Litton Das, Najmul Hossain Shanto, Mahmudullah, Nurul Hasan (wk), Afif Hossain, Mehidy Hasan, Taskin Ahmed, Shoriful Islam, Mustafizur Rahman, Nasum Ahmed