In Tuesday night's round of 32 clash against Parramatta FC in Sydney, Devlin opened the scoring for the visitors on 35 minutes with one of the first real chances of the game.
A dynamic right-foot shot from outside the area putting St Albans 1-0 up at Melita Stadium.
The Victorians held on to register a famous win and now they could face Hyundai A-League opposition in September in the round of 16 of the Westfield FFA Cup.
“It’s a feel I can’t describe, I swear to God,” the Irishman told www.theffacup.com.au moments after the final whistle.
“It’s the beauty of the Cup, eh?
“It’s one of those shots, 100 of them blaze over the bar but this one I caught it sweetly.”
He revealed that playing up front wasn’t his forte after the Saints' regular striker injured a hamstring last week.
“I’m usually centre half so I was thrown up front for this game. Believe or not, that’s my tenth goal of the season, nine have been with my head though.
“But the boys at the back were excellent. Kept a clean sheet. We rode our luck a bit.
"Fair play to Parramatta, but what can I say?
“And with our supporters, they were second to none. I reckon over 500 travelled up.”