Bangladesh has blown away West Indies captain Darren Sammy's hopes for a series whitewash by easily winning the first one-day international by seven wickets with nearly 10 overs to spare on Friday.
Bangladesh dismissed West Indies for 199 in the 47th over, then reached 201-3 in 40.2 overs at Sheikh Abu Naser Divisional Stadium.
Sammy wanted West Indies to sweep all five one-dayers to improve its ranking of seventh, on the back of winning both tests.
But ninth-ranked Bangladesh ruined that plan after Sammy won the toss, elected to bat, and watched his side fail to post a meaningful score.
Bangladesh has won five of the last eight ODIs against West Indies since 2009.
Offspinner Sohag Gazi, who made his debut in the tests this month and played in his first one-dayer, took 4-29, including the key wicket of Chris Gayle, who made 35 off 40 balls. Left-arm spinner Abdur Razzak, who did not play in the tests, added 3-39.
Gazi was one of four making their debut for Bangladesh, along with opener Anamul Haq, who scored 41, Mominul Haq, and Abul Hasan.
Anamul Haq and Tamim Iqbal gave Bangladesh a brilliant start with a stand of 88 in 15 overs before Tamim Iqbal was out for 58 off 51 balls, spun out by Sunil Narine. Tamim Iqbal's 24th ODI half century included hit eight boundaries and two sixes.
Anamul Haq was caught and bowled by Sammy for 41, including seven fours, at 112-2.
Naeem Islam guided Bangladesh to the win with partnerships of 45 with Nasir Hossain (28) and an unbeaten 46 with Mushfiqur Rahim (16 not out).
Naeem Islam was unbeaten on 50, his third half century coming from 79 balls.
Earlier, Gayle and Darren Bravo (35) made good starts but couldn't push on in the face of good bowling.
West Indies slumped to 133-8 and was saved from a worse score only by a 57-run stand for the ninth wicket between Ravi Rampaul (26) and Narine (36), who was last out.