Ireland had caused huge upsets at both their previous World Cups, but it was Scotland, who have yet to taste victory in two tournaments, who won the battle of the Celtic minnows with 23 overs to spare.
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Scotland won the toss and chose to bat but made a faltering start when they lost their top batsman and skipper for the day Kyle Coetzer for a duck in the second over.
They slumped to 2-42 when Hamish Gardner became paceman Max Sorensen's (3-55) second victim in the eighth over but that brought Machan to the crease.
The young left-hander formed partnerships of 44 with Calum MacLeod (41), 96 with Preston Mommsen (56) and 98 with Richie Berrington, who hit his 52 off 40 balls as Scotland accelerated the scoring rate in their final 10 overs.
Machan was finally bowled by Craig Young, having blasted six fours and four sixes in his 108-ball knock, but the Scots were already well on their way to an imposing score of 296 for six.
Ireland started their run chase with a solid opening stand of 57 between skipper William Porterfield and Paul Stirling (37) before Evans struck with a three-wicket blitz in two overs.
The right-arm seamer returned to remove Porterfield for 23 and the Irish were really on the ropes at 77-5 when Andrew Balbirnie followed for eight in the following over.
Ireland's tail were only able to eke out another 40 runs as experienced off-spinner Majid Haq (3-9) and seamer Josh Davey (2-36) got among the wickets to secure a handsome victory.
Ireland get their World Cup campaign underway against West Indies in Nelson next Monday, while the Scots face co-hosts New Zealand in their opener in Dunedin the following day.
Image: Matt Machan
Photograph: Martin Hunter/Getty Images
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