Peru coach Sergio Markarian was furious after his side went down 1-0 to Chile in Tuesday's Pacific 'clasico', a result which gave the Chileans top spot in group C.
Both sides had already assured themselves of passage to the quarter-finals in taking four points from their opening two encounters, leaving Uruguay to play catch-up.
But after Peruvian defender Andre Carrillo had deflected into his own net to settle the affair in injury time Markarian directed his ire at Brazilian referee Salvio Fagundes, who sent off Chile's Jean Beausejour and Peru's Giancarlo Carmona for a mutual flare-up.
Markarian blasted the referees decisions as "tendentious" and also had a dig at the media which he felt had gone too far in whipping up sentiment in the run-up to the game.
"In football you have to be pragmatic," said Markarian, who has his hands full with a Peru side which has disappointed for decades - going back to their second - and so far last - Copa win in 1975.
He felt that referee Fagundes did not have a good game.
"This is the same one who deprived Colombia of a legitimate win against Argentina," insisted Markarian, referrnig to a penalty appeal turned down at the expense of Colombia forward Radamel Falcao Garcia, who felt he had been fouled.
And he was scathing about the red cards.
"Carmona did not deserve to be sent off - though Beausejour did. And that changed the game," he blasted.
Beausejour apologised to his teammates afterwards.
"I am sorry. There is no justification for what I did," said Beausejour after starting the set-to which saw him and Carmona head for an early bath.
"It hurts a lot to miss the next match - I made an inexplicable mistake," said Beausejour.
Carmona was also contrite.
"I feel responsible for the defeat. I don't know if the (red card) decision was justified and it is not for me to decide but the defeat is very sad as we were doing things very well," Carmona said.