Darren Randolph kept a clean sheet, Martin Braithwaite scored and Enes Mamuhtovic was with Luxembourg on another busy night of international football.
Randolph was a virtual spectator as Ireland completed the double of Gibraltar, not that his outfield colleagues found it easy going.
Only an own goal separated the sides until the third minute of injury time when a Robbie Brady header put a bit of distance between the sides in Dublin.
The 2-0 win keeps Ireland top of their qualifying group, five points ahead of Denmark who have a game in hand.
The Danes comfortably won their game against Georgia. Martin Braithwaite came off the bench to score in the 94th minute and seal a 5-1 win in Copenhagen.
Enes Mahmutovic was an unused sub as the top two went head-to-head in L'viv. Ukraine making the most of home advantage, but only just as a single goal against Luxembourg saw Andriy Shevchenko's side extend their lead at the top of the table.
Tonight, Paddy McNair and George Saville hope to create history when Northern Ireland take on Belarus in Borisov.
Michael O'Neill's side sit top of their group having won three from three, but they have never won four successive games in a qualification group.