He had a couple of half-chances to close in on Niall Quinn's all-time scoring record - Robbie is on 19 chasing 21 - but in the end left it to Matt Holland to volley home the winner in the second half.
Gary Doherty was an unused substitute as Roy Keane made his return.
Ireland now travel back to England and the Unity Cup against Nigeria and Jamiaca hosted by Charlton Athletic.
They play Nigeria on Saturday and Jamaica on Wednesday before a final summer friendly against Holland on Saturday week, June 5.
Robbie Keane won his 50th cap for the Republic of Ireland in last night's 1-0 friendly victory against Romania.