Rangers manager Giovanni van Bronckhorst's lasting derby memory comes from Parkhead.
A fan had fallen from the upper tier at Celtic's famous ground and even the players on the park were holding their breath as medics attended to him.
And suddenly, when the home support started up another song, the players saw a clenched fist rise from the stretcher, the man in full participation.
"That injured guy just sang along again," laughed Van Bronckhorst to Rotterdam newspaper Algemeen Dagblad.
He's taken part in El Clasico and the North London derby – but he insists nothing comes close to Glasgow's famous fixture.
A fixture that Ibrox legend Barry Ferguson always wanted to get the Dutchman up for.
"He was really egging me on for that game," Van Bronckhorst added, explaining Ferguson would often tell him 'f*** them' while on the bus.
"What you have achieved before this match, doesn't matter now.
"It is all about Celtic now. I have played many special and big games, but the Old Firm is very special.
"There are no bigger games at club level. Not in the whole world."
Asked if he would meet Celtic boss Ange Postecoglou for a drink after the match, Van Bronckhorst said: "We are playing away, so I have no idea.
"Ange should invite me then, shouldn't he?
"But I'm not thinking about wine or anything. I'm thinking about the Old Firm and our chance to take a five-point lead."
