The score was 1-0 for Peru and Farfan passed to Pizarro. Alone in front of Carini, he struck the ball and the goalkeeper stopped it but couldn't retain it. The ball was picked up by Guerrero, who scored. Amarilla, very badly helped by assistant Placido Chuello from Venezuela - who flagged - invalidated the goal. Huge mistake. Both Pizarro and Guerrero, were never off-side.
This is the problem that Amarilla has. You can nominate him as the best or the worst depending which part of the match you are watching. Lugano was rightly booked, but later Rodriguez committed a big foul against Estoyanoff and was not punished with any card (the referee only whistled). And Pizarro saw yellow because of a little foul. Good calls are often followed by important mistakes with this referee.
Peru was nothing like the team that we saw before the last World Cup. This team is aggressive, keeps its order and is much more concentrated when defending. Now they lead Group A.
In contrast, the "Celeste": huge problems in the defense, losing in midfield and really weak on the attack. They will have to improve a lot if they don't want to return home after the 1st round.