Shiv Chanderpaul hit a superb century as West Indies sealed an eight-wicket win over Ireland in a rain-hit Group D decider in Kingston, Jamaica.
Chasing a revised target of 190 off 48 overs, he hit 10 fours and four sixes in an unbeaten 102 off 113 balls as the Windies raced home off just 38.1 overs.
Ireland lost dangerman Jeremy Bray for 41 and were struggling on 159-6 in the 46th over when the heavens opened.
Dwayne Bravo took two wickets in two balls as they finished on 183-8.
Ireland had already qualified for the next phase after beating Pakistan and securing a tie against Zimbabwe, but were competing for top spot in the group and the two points to carry through to the Super 8s.
606: DEBATE
After managing a modest total against a steady attack, Dave Langford-Smith made an early breakthrough to dismiss the prolific Chris Gayle for 18.
However, Chanderpaul was in inspired form and struck four consecutive fours off Boyd Rankin to put the hosts firmly in control.
The diminutive left-hander followed that with an aggressive straight six that thrilled the exuberant Sabina Park crowd.
He added three more sixes to bring up the 100 stand with Ramnaresh Sarwan off 122 balls, with his contribution being 72 off 62 balls.
Kyle McCallan, skipper in the absence of the injured Trent Johnston, removed Sarwan for 36 but by then the outcome was not in doubt.
Marlon Samuels, who added an undefeated 27 to go alongside Chanderpaul's sixth one-day international century, finished the job with a six over mid-wicket.
Ireland, after winning the toss, made a poor start when William Porterfield edged Daren Powell to Gayle at first slip in the second over with the score 3-1.
Bray rebuilt the innings with an array of savage cuts and lofty off-drives, although he had a lucky escape on 37 when one chest-high cover drive was dropped by Samuels.
Eoin Morgan skied an attempted pull and wicket-keeper Denesh Ramdin won a three-man 40-yard chase to catch him out for 18 and end a promising stand of 58.
Bray, who hit an unbeaten century in the tied match against Zimbabwe, then lost Niall O'Brien and instead of steadying the ship, he lofted a Jerome Taylor slower ball straight to substitute fielder Lendl Simmons at mid-off to end his innings.
Bravo and Gayle, who did not concede a boundary in his 2-23 off 10 overs, kept a tight leash on the batsmen.
Kevin O'Brien fired a Gayle delivery high into the air and into the hands of Sarwan and Andre Botha joined him back in the pavilion after another lofted shot was caught by Ramdin.
Andrew White and McCallan battled on before a shower brought the players off the field for an hour with Ireland 159-6 after 45.2 overs.
Bravo then bowled White, had John Mooney caught behind for a golden duck and rapped Langford-Smith on the pads, but it was veering down the leg-side and his hat-trick appeal was turned down.
McCallan was left unbeaten on 20 at the end of their innings, but the total was not big enough, despite being increased under the Duckworth/Lewis method.
West Indies: Brian Lara (captain), Chris Gayle, Shivnarine Chanderpaul, Ramnaresh Sarwan, Marlon Samuels, Dwayne Bravo, Dwayne Smith, Denesh Ramdin, Ian Bradshaw, Daren Powell, Jerome Taylor.
Ireland: Jeremy Bray, William Porterfield, Eoin Morgan, Niall O'Brien, Andre Botha, Kevin O'Brien, Kyle McCallan (captain), Andrew White, John Mooney, Dave Langford-Smith, Boyd Rankin.
Umpires: Billy Bowden (NZL) and Ian Gould (ENG); 3rd umpire Brian Jerling (RSA) Referee: Roshan Mahanama (SRI)