Dunne’s simply stunning final round of 61 including birdies at his final two holes, one a chip in at the last, earned the 24 year old his first European Tour title and a cheque for €562.500.
Dunne, a former Walker Cup player, led the Open Championship in 2015 at St Andrews through 54 holes but this is his first professional win in his 51st European Tour event after losing out in a play-off to Edoardo Molinari at the Trophée Hassan II in April.
McIlroy stormed home over the weekend with rounds of 64 and 63 himself to catch and pass 54 hole leader Karlsson, finish runner-up and record his best finish anywhere since the BMW SA Open in his first event of 2017.
McIlroy in turn finished one shot clear of Karlsson.
Andrew Dodt was unable to capitalise on his fast start to the tournament but finished as the leading Australian in 37th position, Wade Ormsby was one shot further back in 44th place, the pair the only two Australians to make the cut.
The European Tour is now heading north to Scotland for the Alfred Dunhill Links Championship.
LEE WESTWOOD 500 EUROPEAN TOUR STARTS
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