Basseterre (St Kitts): All-rounder Mahmudullah hit an unbeaten 51 on Friday to push Bangladesh to a tense three-wicket victory and a 3-0 series sweep over West Indies in the third and final one-day cricket international.
The right-hander, who earlier took 2-38 with his off-spin, struck two fours and a six off 70 balls as the visitors reached their target of 249-7 with seven balls to spare.
Junaid Siddique contributed 55 while fellow opener Tamim Iqbal (30), Mushfiqur Rahim (31) and Naeem Islam (26) also posted important contributions.
Fast bowler Kemar Roach claimed 4-63 and Darren Sammy, 2-37 to lead the home team.
Earlier, West Indies was bowled out for 248 off 47.4 overs.
Opener Andre Fletcher topscored with 52 off 42 balls while Sammy (40), captain Floyd Reifer (40) and Travis Dowlin (38).
Mahmudullah, medium pacer Mahbubul Alam (2-42) and left-arm spinner Abdur Razzak (2-63) spearheaded the visitors' attack.
"We were all looking forward to this ODI series and we did well," Shakib said after lifting the Digicel Trophy. "We're very happy."
Shakib, named man of the series for his all-round contributions, praised Mahmudullah's match-winning effort.
"It is a team effort. Everyone is chipping in every time and when the team is under pressure, someone is doing the job for the team," Shakib said.
Siddique and Tamim launched Bangladesh's chase in emphatic fashion with an opening stand of 54 off 50 balls.
But West Indies hit back with some crucial scalps.
Tamim blasted five fours and a six off 27 balls before he slapped Sammy straight to mid-off.
Bangladesh soon slipped to 96-3 once David Bernard Jr. claimed Mohammad Ashraful (19) and Roach scalped Raqibul Hasan (5).
Ashraful edged to the wicket-keeper while Raqibul fell to a sensational low catch at extra cover from Reifer.
Siddique and Shakib added 32 for the fourth wicket but the West Indies seized the initiative as both batsmen fell in quick succession to Roach.
Siddique, after hitting six fours off 73 balls, lost his leg stump to a slower ball while Shakib miscued a pull to extra cover at 133-5.
Roach should have added the wicket of Mahmudullah but Sammy floored a tough, low catch at first slip before the 23-year-old had scored.
Mahmudullah made the most of that let-off and in successive partnerships with Mushfiqur and Naeem, steered his side home.
He added 50 with Mushfiqur before the wicket-keeper was harshly ruled out caught down the leg side off Sammy.
Then, Mahudullh and Naeem put on 49 to set up the series sweep. Naeem fell for 26 off 22 balls to give West Indies a sniff but the visitors held on for the historic win.
Earlier, the West Indies was in early peril after winning the toss and batting on a true pitch.
19-year-old Kieran Powell, on his debut, fell to the second ball of the match as he was trapped plumb lbw by Mahbubul.
Soon afterwards, it was 10-2 when Devon Smith (4) mowed across the line and was bowled by Mahbubul's new ball mate, Nazmul Hossain.
Fletcher and the in-form Travis Dowlin revived the innings in a third wicket stand of 76 off 72 balls.
The 21-year-old Fletcher brought up his maiden one-day fifty, off 40 balls with eight fours and three sixes. But the right-hander perished soon afterwards as he holed out to long-on off Razzak's left-arm spin.
The innings wobbled again as Dowlin was run out after a mix-up with Reifer and Bernard Jr. fell at 124-5 in the 28th over.
Dowlin hesisted on a single and was undone by Ashraful's throw while Bernard (1) lofted to long-on off Mahmudullah.
Reifer, and Sammy again boosted their team with contrasting innings.
Reifer, scratchily compiled 40 off 79 balls with a six and three fours while Sammy blasted five fours and two sixes off 33 balls.
But they fell within two runs of each other as Bangladesh kept a tight rein.
Reifer clipped an ondrive to midwicket off Mahbubul while Sammy tamely hit a return catch to Razzak at 190-7.
Wicket-keeper Devon Thomas rallied the lower order with a composed, unbeaten 29 off 32 balls with two fours.
Nikita Miller (13) and Kemar Roach (10) helped push the total up to 248.