The 20-year-old Palmer Cup player finished on 284-eight under par — six strokes adrift of winner Ben Stow, who also carded a closing 66.
Hurley climbed up the leaderboard dramatically as Cormac Sharvin, who started the final round in the joint lead, moved in the opposite direction.
Hurley’s 66 included a stunning eagle three on the 521-yard 11th and seven birdies. He had two bogeys — on 4 and 9.
Gavin Moynihan from The Island Club who began the final round a stroke off the pace, concluded with a 71 comprising halves of 36 and 35 — three birdies, one bogey and 14 pars — and he finished alongside Hurley on 284.
Sharvin, the 2013 Irish close champion from Ardglass, was still quite respectable in posting a 73 despite making a complete mess of the 12th, on which he dropped four strokes for a miserable nine.
Apart from that, he had just one bogey and five birdies.
Robin Dawson from Faithlegg carded a closing 69 to move up to joint 12th with a 288 aggregate with Dermot McElroy on 291, Daniel Holland on 297, Paul McBride on 300 and Stuart Grehan on 303.
Meanwhile Denmark’s Emily Pedersen won the Ladies British Open Amateur Championship at Royal St George’s, Sandwich when she beat Belgium’s Leslie Cloots 3&1 in the final.