Mexico brushed aside the news that five of their players had been suspended following failed drugs tests to defeat Cuba 5-0.
It was the Mexicans' second five-goal success in as many games, as well as Cuba's second five-goal reverse.
Manchester United striker Javier Hernandez followed up his opening day hat-trick against El Salvador with two more goals, in the 36th and 76th minutes.
Giovani Dos Santos weighed in with two of his own in the space of five second-half minutes and substitute Aldo de Negris also found the net.
Randall Brenes scored five minutes into added time to rescue a draw for Costa Rica in their Gold Cup Group A clash with El Salvador in North Carolina.
The teams came into the match on the back of polar opposite results - Costa Rica despatching Cuba 5-0 and El Salvador hammered by the same margin by Mexico.
But that meant little when Rodolfo Zelaya put El Salvador in front on the stroke of half-time with a fine free-kick.
Brenes entered the fray in the 80th minute and there were only seconds left from six extra minutes when he fired low past Miguel Montes.