Ajax's fans are a raucous bunch, with the Dutch side's supporters among the most passionate in Europe.
They did however get more than a little over-exuberant ahead of their Dutch Cup Final yesterday, and a former hero had to appeal to them to calm down.
Edwin van der Sar, a Champions League winner with the club in 1995 and Manchester United in 2008, was the sensible head needed.
Ajax had taken an early lead against PEC Zwolle thanks to a Ricardo van Rhijn goal, only to concede two quickly, and were 2-1 down by the 11th minute.
At this point fans became rowdy and started throwing flares onto the pitch, causing the game to be delayed.
The game was only restarted after Van der Sar, part of the club's non-playing staff, entered the pitch with a microphone and appealed for calm, warning:
"Stop throwing fireworks on the field, it's dangerous, if it happens again, the game is abandoned."
The game was able to be restarted, but Ajax fans may have wished it wasn't.
Zwolle, presently ninth in the Eredivisie, scored soon after and Ajax had no answer for them all afternoon.
They ran out 5-1 winners to lift the KNVB Cup for the first time ever in their history.