Roston Chase (46), Jonathan Carter (43*) and Jason Holder (36) all chipped in but it was Ambris who looked class apart and completed his maiden century.
In reply, Ireland were bowled out for mere 185 in 34.4 overs. However, with Stirling on 77, he hooked a Shannon Gabriel bouncer straight into the hands of fine leg. William Porterfield fell soon after for 3, however, Kevin O'Brien proved to be the ideal foil for Balbirnie, who continued to push along at a run a ball before completing his hundred off his hundredth ball.
Hope fell in the 13th over to a fantastic catch at point by James McCollum off former England fast bowler Boyd Rankin and Darren Bravo was caught on the long-off boundary for 17 off Paul Stirling's off-spin.
"It wasn't best day in the office", Ireland all-rounder Kevin O'Brien said after his side failed to catch the Windies' 381, according to RTE. O'Brien, who had batted with great intent from the off, deposited Jason Holder for three sixes in a row in the 48th over.
The Caribbean duo were only seven runs shy of the record partnership for any wicket in a men's ODI, with their fellow West Indians Chris Gayle and Marlon Samuels smashing 372 for the second wicket against Zimbabwe in Canberra during the 2015 World Cup. He grabbed his chance though, and was confident right from the start, feasting on some ordinary bowling by Ireland to ensure West Indies' chase never flagged.
Campbell missed out on the second match against Bangladesh, but Hope continued to keep his good form going, as he hit another century to allow West Indies to post a respectable total on the board. However, Stirling and Balbirnie set the foundation for a healthy score with a stand of 146 for the second wicket.
The win books West Indies place in Friday's Tri-series final and Ireland must beat Bangladesh on Wednesday at Clontarf and hope the Windies beat the Tigers here tomorrow to have a chance of joining them. With the duo adding more than a hundred runs for the third wicket, West Indies were well and truly in the ascendancy.
West Indies captan Jaosn Holder.
"I've felt good for the last two games and found myself getting out weirdly, I felt quite good in training and that I was moving quite well so to be able to put on a big score as a team, as a batting group was very pleasing".