Referee Carlos Maglio realised that even after dishing out eight bookings in a friendly between bitter Argentine rivals Estudiantes and Gimnasia the players were not getting the message, so he relinquished his yellow card to send a clear warning: the next one's red.
"Retiring the yellow was a spur of the moment decision. I had already booked eight players and I didn't want them to keep on hitting each other," Maglio told La Red radio.
Maglio handed over his yellow card to one of his assistants during the second half of Sunday's 1-1 draw in the seaside resort of Mar del Plata in a friendly played during the season's summer break.
Sooner afterwards, Maglio sent off Estudiantes midfielder Israel Damonte for violent play.
"The fourth official asked me to give it to him so that everyone should see (the decision)," he added. "That way it was clear to everyone that the yellow was no longer in play."
Maglio said the decision worked out well. There were no further cards issued after Damonte's dismissal in the 84th minute.
"Even if I'd had the yellow card he would still have gone off," said the ref of Damonte. "It was a red (card) offence."
There is rarely anything amicable about summer friendlies in Argentina, often between classic rivals like the two clubs from La Plata, who use them to gear up for the second half of the season starting in February.