Kyle Mayers smashed a sensational century in his debut match as the West Indies registered an unlikely victory on Sunday.
Mayers made an unbeaten 210 while fellow debutant Nkrumah Bonner scored 86 as the West Indies overhauled the target with three wickets remaining at the very end of the Test in Chittagong.
Mayers fittingly hit the winning run with just 1.3 overs left on the final day to complete the stunning run chase. Mehidy Hasan picked up 4/113 for Bangladesh.
The second Test of the two-match series starts in Dhaka on February 11.
The result meant West Indies achieved the fifth highest total of all time in the fourth innings of a Test match win. It was also the highest successful Test run-chase in Asia.
In the final session, they had needed 129 runs from a minimum 33 overs to win.
Resuming on 110/3, the pair on debut frustrated the Bangladesh bowlers and took their partnership to 216.
Bonner pulled off-spinner Mehidy Hasan over square leg for a boundary with the first ball of the day and Mayers brought up the century stand by hitting Mustafizur Rahman for a four and six off successive deliveries.
Mayer became the 15th West Indies batsman to get a debut century when he edged a Mustafizur ball to the boundary between slip and gully.
Bangladesh scored 430 and 223/8 declared. The West Indies made 259 in their first innings.
After two disappointing sessions, Taijul Islam finally gave Bangladesh some hope, dismissing Bonner in the first over after tea.
Bangladesh then appeared to tighten its grip on the match as offspinner Nayeem Hasan dismissed Jermaine Blackwood for 9, leaving the West Indies at 292/5.
But Mayers continued his spectacular attack with wicketkeeper Joshua Da Silva giving him the necessary support to seal the victory.
Silva scored just 20 in their 100-run partnership and was out just three runs away from victory.
Mayers, meanwhile, brought up his double hundred off 303 balls with a gentle punch to deep backward point for a single. He then hit his seventh six to put the tourists on the verge of the victory before pushing one off Nayeem Hasan to mid-on for a single to confirm the victory.