Aaron Finch's fifty revives T20 World Cup campaign, hands Australia 42-run win over Ireland

Skipper Aaron Finch returned to form with an aggressive half-century as defending champions Australia revived their T20 World Cup campaign with a 42-run win over Ireland, here on Monday.

Finch, who struggled with a hamstring issue, revived Australia's innings with a 44-ball 63 as the hosts overcame a slow start to post a competitive 179 for five after being sent into bat.

Chasing the imposing total, Ireland, who knocked out two-time champions West Indies and shocked England in the Super 12 stage, were dismissed for 137 in 18.1 overs.

By virtue of this win, Australia, with five points from four games, jumped to second spot in Group 1 ahead of England to be in the reckoning for a semifinal spot. New Zealand are leading the group.

Australia will take on Afghanistan in their last group game on Friday in Adelaide.

Australia rode on their pace prowess to dismiss half of the Irish side inside four overs with the scoreboard reading 25.

Wicketkeeper-batter Lorcan Tucker stood tall for Ireland with the bat as he hit a counter-attacking unbeaten 71 off 48 balls to keep his side's hopes alive.

But with little support from the other end, it was too much of an asking from Tucker and it was all over for Ireland after Joshua Little was ran out in the penultimate over.

Pace spearhead Pat Cummins (2/28) started it all, cleaning up Ireland's in-form opener Andy Balbirnie (6) before Glenn Maxwell (2/14) dismissed Paul Stirling (11) and Harry Tector (6) within a span of five balls.

Mitchell Starc (2/43) then produced a sensational opening over, cleaning up Harry Tector (6) and Curtis Campher (0) in a span of five balls to reduce Ireland to 25 for five.

But Tucker was in no mood to give up without a fight and stitched a 43-run stand off 33 balls with Gareth Delany to keep them in the hunt.

Tucker also smashed Mitchell Starc for 12 runs, including two back-to-back boundaries in the 12th over. Luck also favoured Tucker as Cummins dropped him on 35 in the same eventful over of Starc.

Earlier struggling for runs, Finch brilliantly switched gears to reach his 50 off 38 balls -- his first T20 International half-century in eight innings -- and together with Marcus Stoinis (35) shared an entertaining 70-run partnership. But the skipper, however, could not finish well and became Irish pacer McCarthy's third victim in the 17th over as the defending champions struggled to get going at the death, falling some 15-20 runs short.

Left-arm spinner George Dockrell (4-0-24-0) conceded just three runs in the 18th over, while left-arm pacer Josh Little (4-0-21-2) also finished well, dismissing Stoinis and giving away just four runs in the penultimate over.

McCarthy was the pick of the Irish bowlers, returning with 3/29, including the wickets of David Warner (3) and Mitchell Marsh (28) who looked ominous with a 102-metre six but only to fall for 22-ball 28.

But the Aussies managed to get going in the final over with Tim David hitting two boundaries en route to 10-ball 15 to push the total.