And the 34-year-old fly-half produced the goods for the second week running with the final play from 40 yards out at the Stade Ernest Wallon to earn Munster their second pool triumph from two matches.
Tries from Doug Howlett, Peter O'Mahony and Will Chambers helped set up the grandstand finish and McGahan insists last week's heroics ensured his players kept the faith they could replicate the dramatic finish.
"I think it's a little bit of belief and probably a little bit more confidence," said McGahan.
"We talked about 41 phases last week to get the drop goal and to do it two weeks on the bounce is certainly incredible.
"We relied on the other 22 players to make sure they were in a position to put Ronan in that position and, as I said last week, he's certainly a special player.
"We went through some harsh lessons last year as a group and so you certainly want to be learning those in going forward."
63x46.png){kind=logo}