ICC Women's T20 World Cup, Cape Town:
Ireland 137-9 (20 overs): Prendergast 61, Lewis 38; Connell 3-24
West Indies 140-4 (19.5 overs): Matthews 63*, Henry 34
West Indies won by six wickets
Captain Hayley Matthews struck an unbeaten 63 to help West Indies beat Ireland with one ball to spare to keep their slim hopes of making the Women's T20 World Cup semi-finals alive.
Matthews hit the penultimate ball for four as West Indies chased down their target of 138 in a thrilling finish.
Earlier, Orla Prendergast had hit 61 off 47 balls as Ireland posted 137-9.
Ireland, who looked like favourites at the halfway stage, were eliminated with the defeat in Cape Town.
West Indies must beat Pakistan by a large margin in their last game on Sunday to improve their net run-rate - and also need one of England or India to lose both of their remaining games to have any chance of qualifying in second place.
Ireland were hoping to record their first ever T20 World Cup win, having lost all of their previous 14 matches, and were anchored by Prendergast and Gaby Lewis' (38) 90-run partnership.
At 115-2 after 15 overs they looked set for a menacing total, but added just 22 more runs for seven wickets across the final 30 deliveries.
West Indies' Matthews was dropped on nine by Amy Hunter at backward point in the fifth over and it was an error which proved to be costly.
Alongside Chinelle Henry (34) Matthews built a 74-run partnership before Ireland rallied in the final overs.
Needing two runs from the final two deliveries Matthews carved Ireland skipper Laura Delany through the covers for four to end West Indies' 15-match T20I losing streak.