Buoyed by a century from Tamim Iqbal, some good bowling and work in the field coupled with the West Indies' struggles in the middle overs, Bangladesh secured a somewhat nervy 18-run win in the series-deciding ODI in Basseterre to seal a 2-1 win yesterday.

It was Bangladesh's first series win outside Asia since 2009 and an important result considering the manner of that 2-0 series defeat in the preceding Tests, where the visitors failed to cross the 200-run mark in any of their four innings.

Bangladesh posted 301 after Mashrafe Bin Mortaza had won the toss and opted to bat as opener Tamim Iqbal hit back at his critics and laid the platform with a fine century, his second in three games.

The experienced left-hander, who came under fire for his slow pace in the second ODI which Bangladesh lost by three runs, hammered 103 off 124 balls, smiting seven fours and a couple of sixes.

Shakib Al Hasan joined Tamim after his opening partner Anamul Haque departed for a disappointing 10 off 31 and the pair added 81 runs before Shakib departed for a well-compiled 37 off 44 balls, top-edging off-spinner Ashley Nurse.

Mushfiqur Rahim did not last long, scoring 12 off 14 balls before Mahmudullah Riyad and Tamim Iqbal put on 48 runs.

Tamim's dismissal in the 39th over with the score at 200 prompted Mashrafe to come onto the pitch and he added 53 runs with Mahmudullah, with the skipper shouldering the run-scoring duties. He hit a 25-ball 36 with some lusty blows before departing.

Mahmudullah continued the late surge, finishing the innings unbeaten on a 49-ball 67 that included five fours and three sixes to take Bangladesh past the 300-run mark.

After the exchange, Bangladesh looked to be in trouble as Chris Gayle began to go great guns.

The self-styled 'Universe Boss' hit 73 off 66 balls, hammering six fours and five sixes, one of which was hit out of the park.

Nobody was safe from Gayle's onslaught, not even his a scampering young lad who was hit in the back as Gayle launched Mashrafe over extra cover for six in the eight over.

However, his struggling partner Evin Lewis was dismissed in the tenth over by Mashrafe -- as in the two previous matches -- for a labored 33-ball 13 that featured only one four.

Shai Hope came in to join Gayle but he struggled to rotate the strike or get runs under his belt. Given that Hope -- who has the worst strike rate in the past two years among batsmen who have scored at least 1,000 runs -- was struggling, Gayle looked for one big shot too many and was caught by Mehedi off Rubel's bowling.

And after Shimron Hetmyer had departed for a 42-ball 30, Hope was responsible for another dismissal, causing a horrible mix-up that saw Kieron Powell stranded in the middle of the track, which left the hosts on 179 for four at the end of the 38th over.

There were some late attempts at heroics from West Indies batsman Rovman Powell, who did not play a dot ball till his 32nd delivery and brought up his half-century inside just 27 balls.

However, it was not enough and Bangladesh held on for an ultimately comfortable win.

SCORES IN BRIEF

Bangladesh: 301 for 6 in 50 overs (Tamim 103, Shakib 37, Mahmudullah 67, Mashrafee 36; Holder 2-55, Nurse 2-53)

West Indies: 283 for 6 in 50 overs (Gayle 73, Hope 64, Hetmyer 30, R Powell 74 not out; Mashrafee 2-63, Rubel 1-34)

Result: Bangladesh won by 18 runs

Man-of-the-match: Tamim Iqbal