Tamim Iqbal and Naeem Islam scored half-centuries while Sohag Gazi took four wickets as Bangladesh beat the West Indies by seven wickets in the first one-day match in Khulna on Friday.
Iqbal smashed a 51-ball 58 studded with eight fours and two sixes while Islam finished with an unbeaten 50 as the hosts achieved a modest 200-run target with 9.2 overs to spare, for a 1-0 lead in the five-match series.
Gazi took 4-29, the best figures by a Bangldeshi bowler on one-day debut, to restrict the West Indies to 199 after they won the toss and opted to bat.
Iqbal and Anamul Haque (41) put on a solid 88-run opening stand to ensure the hosts, who were missing key all-rounder Shakib Al Hasan through injury, did not spoil the good work by their bowlers.
Iqbal thumped West Indian spearhead Kemar Roach for two fours and a six in one over to reach his 24th one-day fifty before playing straight into the hands of point off spinner Sunil Narine.
Haque hit seven boundaries off 62 balls before giving a return catch to West Indian skipper Darren Sammy.
West Indies innings
L Simmons lbw b Mortaza 13
C Gayle c Tamim b Gazi 35
D Bravo run out 35
M Samuels c Mahmudullah b Gazi 0
K Pollard c Mortaza b Razzak 15
D Thomas c Razzak b Gazi 16
D Sammy c Naeem b Mahmudullah 10
A Russell b Razzak 0
S Narine lbw b Gazi 36
R Rampaul c Rahim b Razzak 25
K Roach not out 3
Total (all out; 46.5 overs) 199
Fall of wickets: 1-48 2-48 3-50 4-100 5-102 6-128 7-130 8-133 9-190
T Iqbal c Pollard b Narine 58
A Haque c&b Sammy 41
N Islam not out 50
N Hossain c Pollard b Russell 28
M Rahim 16
Total (three wickets; 40.2 overs) 201
Fall of wickets: 1-88 2-112 3-157
Islam, who hit six fours in his sedate 79-ball knock, shared a 45-run third wicket stand with Nasir Hossain (28) as the hosts comfortably registered a sweet comeback win after losing the Test series 2-0.
"Our quicks set the platform, the spinners backed them up," Bangladesh captain Mushfiqur Rahim said.
"There were a couple of individual performances in Tests but not combined. Today we played as a team, so I am happy."
West Indian captain Darren Sammy said the hosts were worthy winners.
"Credit to Bangladesh, they had a plan, they stuck to it, and they deserved to win. We just didn't execute today, there is no sense of panic in the dressing room. There are four games to go, I am sure we can come back," he said.
Earlier, 21-year-old off-spinner Gazi derailed the West Indians by dismissing Chris Gayle off the second ball of his one-day career for 35 and had Marlon Samuels (nought) in his second over.
Gayle, who hit four fours and two sixes during his 40-ball knock, gave the West Indies a sound 48-run start with Lendl Simmons (13) but once the spinners came on to bowl the batsmen struggled.
The West Indies were in danger of getting out for below the 150-mark but Narine, who top-scored with 36, added 57 for the ninth wicket with Ravi Rampaul (25) to lift the total.
Gazi, who also dismissed Devon Thomas for 16, ended the innings by trapping Narine leg-before in the 47th over to improve on Rubel Hossain's 4-33 against Sri Lanka in Dhaka in 2009 - the previous best ODI figures on debut by a Bangladeshi.
Darren Bravo also shaped well for his 41-ball 35 which included four fours and a six before he was run out as the West Indies lost their way from 100-3 to 133-8.
Left-arm spinner Abdur Razzak dismissed big-hitters Kieron Pollard (15) and Andre Russell (nought) before taking the wicket of Rampaul to finish with 3-39.
The second match will also be played in Khulna on Sunday.