Slogans. Paltry fines. Captains reading out prepared statements over the Tannoy. More paltry fines. T-shirts. Even more paltry fines … When nothing meaningful changes, when words appear to fall on deliberately deaf ears, when punishments are forgotten as quickly as a hastily written cheque, when the authorities do not help, eventually there comes a time for direct action.

A brave and eloquent message in football's attempt to stem the poisonous undercurrent of racism came from the boot of Kevin-Prince Boateng, the Milan player who on a crisp, sunny day during a friendly match to keep the players ticking over during the winter break, simply had enough.

The context is meaningful. The Rossoneri were in action against Pro Patria, a fourth tier team from Lombardy based around 25km north of Milan. It is a weekday afternoon. It is the holidays. It is a friendly. It is a little stadium with a capacity of under 5,000. Maybe you might want to take your kids along to get a close-up view of some of Milan's stars. Maybe you might think it is appropriate under those circumstances to aim racist insults at some of those very players. Shamefully, unbelievably, some people evidently did.

Midway through the first half, Boateng could take it no longer. He was in possession, near the flank where his tormentors were stationed. He picked up the ball and struck it into their general direction. Visibly upset, he headed for the tunnel. The referee and a group of players from both teams attempted to talk to him, but nothing could be said to change the course of this human response – and in the wider context of things this brilliant and vital response.

Boateng removed his shirt and walked. Spontaneously – and this is also significant – applause broke out from the majority of the crowd. Boateng put his shirt around his neck and applauded back. In that moment, there was recognition that his act of defiance was beyond question.

There are those who argue that this kind of protest is letting the aggressors win, that the best way to counter it is to ignore it and keep playing. But it is hard to sustain that argument when it does not work. The aggressors have clearly not got the message yet via any other attempts to consign such moronic behaviour to the dustbin.

It is in Uefa's powers to punish Milan for leaving the field without the referee taking the decision to abandon the match, although hopefully the rules may not be so thorough for unofficial matches. But unless the game's governing bodies choose a path to deal with racist taunting more effectively, maybe action like this is coming in a competitive game. Maybe one day a white player might even feel compelled to take the lead and take the decision to end a game in support of one of their own.

Watching the way Boateng's team-mates determinedly and instinctively followed him off the pitch, the case of Marco Zoro came to mind. Zoro is a defender from the Ivory Coast who was playing for Messina in November 2005 when he was the victim of racist abuse from a group affiliated to Internazionale. He, too, was distraught enough to leave the field. Notably, though, he was persuaded to come back and play on, particularly by Adriano and Obafemi Martins. Other players did not want to back him then, so this is progress of sorts.

There was condemnation in Italy then. There will be condemnation in Italy now following events at Pro Patria. Milan's coach, Massimiliano Allegri, noted the need for education. Not only should people not be behaving in this way in 2013, they should not even be thinking it.

"Shame these things still happen," tweeted Boateng. Shame, indeed, in every sense of the word, although Boateng's brave stance should be lauded.