Penarol vs. Nacional preseason friendly costs Pablo Bengoechea his job?

Naturally the headlines regarding South American football have gone to this weekend's River Plate vs. Boca Juniors match in Argentina. How on earth could a high summer preseason friendly produce the level of animosity that leads to five red cards?

Then again, these big, traditional South American derbies can be a law unto themselves. Reason goes out the window, emotion takes over and gets out of hand -- this was even clearer, perhaps, across the water in Uruguay.

The big Montevideo derby, even older than Boca vs. River, is Penarol vs. Nacional. As so often in these South American clashes, there is more than a touch of social class in the clubs' self-images. Penarol are referred to -- at first in a derogatory manner but now worn as a badge of pride -- as the "manyamierda" or "the eaters of excrement," with a historic support base of poor Italian immigrants. Nacional, more associated with the Spanish, would consider themselves a cut above.

Whatever the relevance of these labels to the modern day, theirs is a rivalry that cuts deep. Preseason friendlies between them can often end in brawls -- and now one such match has cost a coach his job.

Last December Pablo Bengoechea took Penarol to the Uruguayan title. It's true that it was not the most eye-catching of championship wins, but they still ended the season ahead of the pack. Along with veterans such as Diego Forlan and Marcelo Zalayeta, Bengoechea gave valuable experience to youngsters such as goalkeeper Gaston Guruceaga and central midfielder Nahitan Nandez, players who could be destined to play an important role in the future of the Uruguayan national team.

Moreover, Bengoechea himself is a former star of the Uruguayan national side and a Penarol idol. He was a wonderfully talented attacking midfielder who spent a decade in the club's striking yellow and black colours. Going into 2016, he must have thought he had enough credit in the bank to take Penarol into their 43rd Copa Libertadores campaign.

That must have seemed all the more true after his side met Nacional in the first of their pre-season friendlies. After a 1-1 draw Penarol won a penalty shoot-out and Bengoechea's thoughts may well have turned to the start of the domestic campaign and a Libertadores debut on Feb. 18 at Sporting Cristal of Peru, a country where he has strong connections. Before taking over at Penarol, Bengoechea was in charge of the Peruvian national team, and may have been looking forward to catching up with old friends.

But then came a second pre-season friendly. This time Nacional were the better side, deservedly winning 3-1. The rumours started to fly and sure enough, soon afterwards Bengoechea was on his way.

On Sunday Penarol announced that their new coach would be Jorge Da Silva, another famous old name who had a successful spell in charge of the club in 2012-13. Penarol's statement recognised that the decision to part company with a club idol had not been an easy one, also stressing that "Bengoechea's departure is not because of one game."

Maybe not. But had his side won that match or lost by the same scoreline to any opponent other than Nacional, it is overwhelmingly likely that Pablo Bengoechea would still be in charge of Penarol.