It marked an impressive debut for coach Noel King, who replaced Don Givens after a poor qualifying campaign for the European Championship.
"Three points and a clean sheet is what we were looking for, but we got a bit of champagne football at the end," said King.
"The last 15 minutes were unbelievable. But fair play to the lads, their attitude was great, they stuck to their task and played well.
"In the opening 10 minutes we could have been a goal or two down, and at the start of the second half we could have conceded a goal, so there's plenty of work to be done.
"We won't be getting carried away with anything, but this was certainly very encouraging."
Two goals from Anthony Stokes got the Irish on their way, with James McCarthy, Seamus Coleman and Owen Garvan completing the scoring.