The striker equalled Niall Quinn's 21-goal haul for the Republic with a second-half penalty as Brian Kerr's men cruised to a 3-0 victory against Cyprus in their World Cup qualifying opener.
Robbie, who only turned 24 in July, has reached Quinn's mark in just 53 internationals.
"This was a great result for us and it was a great team performance as well," he reflected afterwards.
"It was a special moment for me to equal the record and I would like to dedicate it to my father."
Robbie's father, Robbie snr, sadly died of cancer last year.
Boss Kerr added: "I am pleased for Robbie. That goal now takes some of the pressure off him."
Robbie Keane dedicated his record-equalling goal for the Republic of Ireland to the memory of his late father.