Set just 114 to win, the home side collapsed to 88 all out in 16.4 overs, confounded by four run-outs and a fine spell from debutant left-arm spinner Garey Mathurin, who took three for nine in his four overs.
It was England's lowest score in a Twenty20, 23 runs worse than their previous lowest against South Africa two years ago.
England had won the first game on Friday by 10 wickets and looked set for another easy victory as only Marlon Samuels with 35 in 35 balls showed much fire.
The visitors could only muster 113-5 and no less than half the balls faced proved to be dot balls.
But Mathurin, called to the squad only a week ago as a late replacement, turned the tide and England lost wickets regularly with only Ben Stokes (31) providing much fight.
It was a disappointing end to the season for England after hugely successful campaigns throughout the summer against India and Sri Lanka.
