The Heineken Cup final of 2000 catapulted him centre stage and he played the leading role subsequently on many occasions. And he did so with aplomb for Munster and Ireland not just creating records but establishing ones that will never be surpassed.
The 36 year old could never be accused of being 'shy and retiring', preferring to shoot from the hip on-field and from the lip off it when he deemed it necessary.
He caused a huge furore in the run up to the 2006 Heineken Cup opener against Leicester Tigers with controversial remarks about English players and then backed it up by orchestrating the win capped by his fantastic 52 metre penalty on the stroke of full time for a 21-19 victory.
Teammate that day and scorer of a try, Donncha O'Callaghan, O'Gara's roomy so many times with Munster and Ireland had this to say. " To gauge the impact this (retirement) will have you have to understand the phenomenal type of character he is.
"Every day he turns up for training, he brings a standard, sets that standard and never drops it an inch. And expects no less from anyone else no matter whether that's with Munster, Ireland, the Lions, makes no difference to him.
"There are so many players, and I include myself top of that list, who are so much better players for being around him."
Munster Rugby Chief Executive Garrett Fitzgerald said: "In wishing Ronan the very best in the future, I'd like to acknowledge the immense contribution he has made to Munster Rugby and indeed rugby in general in Ireland over the course of what has been a fabulous career.
The longevity of that career is a testimony to his dedication, commitment and professionalism and a marvellous example to others."