Medium-pace bowler Sandeep Sharma took 5-18 to help restrict Mumbai to 179-9
Gayle struck seven sixes in an unbeaten 88 as the West Indians comfortably surpassed Ireland’s 130 for seven.
They got to their target with 24 balls to spare after left-hander Gayle unleashed his explosive batting.
They had made 77 for one by the halfway stage of their chase, of which Gayle contributed 50, and his savage assault on off-spinner Kyle McCallan’s third over yielded two of his clearances of the ropes.
Two more came in the decisive 16th over, sent down by medium pacer John Mooney, as Ireland’s back-up bowlers took a pounding.
Ireland’s single success with the ball came in the eighth over when youngster Andre Fletcher, who impressed with his sheer power, miscued an expansive stroke from McCallan’s second delivery and was caught at point.
Earlier, West Indies restricted tournament outsiders Ireland to just over a run a ball. A lack of batting firepower was exposed by Gayle’s team, who have endured a torrid time against England so far this summer in both Test and one-day cricket.
William Porterfield’s men, who defeated Holland in an extra-over eliminator at Lord’s on Monday, failed to make the most of the powerplay period.
A position of 36 for one at the end of the fielding restrictions severely dented hopes of a challenging total on a traditionally fast-scoring ground.
Northamptonshire’s Niall O’Brien attempted to be the top-order aggressor and was just getting into his stride when he picked out midwicket with a pull off Dwayne Bravo. Ireland particularly struggled against the sheer pace of Fidel Edwards, who followed up his good recent form in the second season of the Indian Premier League with figures of 3-0-13-1.
Medium-pace bowler Sandeep Sharma took 5-18 to help restrict Mumbai to 179-9
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