Arbitro! Chile, Argentina go down to 10 after two first-half red cards

Alexis Sanchez - Chile - fouled by Argentina during CAC final

The first half of Sunday's Copa America Centenario final was breathless, dramatic and controversial -- but it had as much to do with the referee as the players. 

With both Chile and Argentina pressing relentlessly and getting stuck in all over the field, Brazilian referee Heber Lopes largely let the action flow in the early going, then suddenly began brandishing cards left, right and center, leaving both sides playing shorthanded by the time halftime arrived. 

Chile's Marcelo Diaz was awarded his second yellow card in only the 28th minute for impeding a mazy Lionel Messi run.

But just when it seemed that the defending Copa champions were stuck behind the 8 ball, Lopes produced a straight red for Argentine defender Marcos Rojo after a tackle from behind on Arturo Vidal in the 43rd minute.

The ejections were two of six bookings in the first 45 minutes. Were they justified? Let us know what you think.