It was the Ireland out half’s drop goal with the last kick of the game which sealed the points after Dan Parks had looked like securing the win with a penalty moments earlier.
The Scots had led 6-3 just into the second quarter with two Parks penalties against one from O’Gara but then extended their lead when Sean Lamont had made a cutting run to find Donny Macfadyen who was able to blast over, with Parks converting to open a 10 point lead.
However the visitors came straight back and had narrowed the gap at the interval through a Frankie Sheahan touchdown.
Munster took the game to the home side right after the break with Christian Cullen scoring his fifth try of the season, and O’Gara converting however the ding-dong battle continued as Andy Henderson collected Glasgow’s second try, with Parks again on the mark with the kick.
Again Munster reacted immediately and they replied with a simple score from Anthony Horgan – goaled from the widest possible angle by O’Gara to set up a tense finale.
Cullen then completed his double to give his side the lead before Parks took Glasgow Rugby back in front for what seemed like the win. However O’Gara was to have the last say as the Irish side secured the narrowest of victories.
After the game skipper Anthony Foley was full of praise for O’Gara’s heroics. "We have a very reliable kicker in Ronan, we put him into the position to drop the goal and he executed it well."
"We were kicking ourselves inside as we reckoned we should not have been in that situation, we got to 25-20 up and we let Glasgow back into the game by poor defence – that’s something we have to rectify," added Foley.