isso foi a gota d'água
(that was the drop of water) •
In Brazilian Portuguese we say "isso foi a gota d'água", which means "this was the drop of water", literally "the drop that was missing for the glass to overflow". It means that an action has exceeded the limit of something that was already saturated.
"Esse atraso no trabalho foi a gota d'água para ele ser despedido."
"This delay in work was the drop of water for him to be fired."