Leeward Islands were hanging by a thread after they were undermined by a strong all-round performance from Windward Islands captain Liam Sebastien here Thursday.
At the close on the second day of the final round Regional Four-Day contest at the Vivian Richards Cricket Ground, the Leewards were 158 for nine in their second innings, only 19 runs ahead overall.
They were undone by Sebastien who picked up four for 30 with his off-spin, with West Indies off-spinner Shane Shillingford supporting with three for 45.
Left-handed West Indies opener Kieran Powell top scored again with 51, facing 93 balls in 111 minutes at the crease, and striking four fours and a six.
Devon Thomas, meanwhile, hit 28 from 45 balls with two boundaries as he and Powell put on 62 for the second wicket.
Earlier, Sebastien missed out on a third first class century when he fell for 93 as the Windwards, resuming the day on 131 for five, were bowled out for 268.
The left-handed Sebastien, unbeaten on 51 at the start, faced 153 balls in 185 minutes and counted nine boundaries.
He lost Lyndon James early in the day adding just one to his overnight 20 but found an ally in Shillingford with whom he added 87 for the ninth wicket.
Shillingford hammered 42 from 70 balls with four fours and two sixes while Garey Mathurin weighed in with 30 from 43 balls with four boundaries.
Left-arm spinner Yannick Leonard claimed four for 63 while medium pacer Sherwin Peters finished with three for 19.