After scoring his penalty in the shoot-out against Once Caldas at the end of the World Club Cup final, Porto midfielder Diego swore at the goalkeeper and was rightly sent off.
The young Brazilian's action was foolish and immature, but it was understandable.
Diego had come up against Once Caldas twice earlier in the year while he was still playing for Santos.
The teams met in the quarter-finals of the Copa Libertadores, and the approach of Once Caldas was the same as the one they showed in Sunday's clash between the champions of Europe and South America.
The Colombian side refuse to assume any of the risks of the game.
They pull everyone behind the line of the ball and hope that the opposition will be suckered into making a mistake.
Their lack of ambition can kill the game stone dead.
It may well be the only way that a provincial team from Colombia can compete against the best in the world, but it is not always easy to watch, and must be awful to play against.
Diego, for one, would be happy never to have to face Once Caldas again.
His frustration is a tribute to the success with which Caldas carry out their game plan.
There are plenty of things to admire in their play.
They are a defensive side, but not a dirty one: they picked up just two yellow cards in 120 minutes against Porto.
Their aim is not to commit fouls - some of their most awkward moments came against free-kicks struck into their box.
Their defensive system seeks to deny space to the opposition. It requires good organisation and hard work.
It also needs ability - defending deep means that many times they win the ball close to their own goal, in zones where a poor pass out of defence could be fatal.
Once Caldas employ a simple but effective gameplan
But they are comfortable in possession: they work their triangles in midfield, try to draw the opposition forward and spring one of their wide midfielders.
So sweat and talent have played a key part in Once Caldas winning the Copa Libertadores and then coming within a whisker of beating Porto in the penalty shoot-out.
As in all triumphs, luck was also part of the mix.
In the knock-out stages of the Libertadores the luck of the draw meant that Caldas played all of their second-leg ties at home, which fitted in perfectly with their idea of grinding out a draw away and sneaking a win in front of their own fans.
They rode their luck on Sunday against Porto. Porto battered the woodwork and had a goal harshly ruled out for offside, while the Colombians held on and waited for penalties.
When Porto keeper Vitor Baia was taken unwell in extra-time then fortune appeared to have moved once and for all to
But then their luck ran out.
In the shoot-out Porto's substitute keeper Nuno failed to get near a single penalty, while Once Caldas' outstanding Henao got close to almost all of Porto's kicks.
But he couldn't quite make the vital save, and in the end, when it mattered, fortune favoured the side who had spent 120 minutes in search of a goal.