Finally, on July 23, 1941, the Peruvians launched a major invasion, crossing the Zarumilla river in force and advancing into the Ecuadorian province of El Oro.
Nakoniec 23 júla 1941 Peruánci spustili hlavnú inváziu, prekročili rieku Zarumilla a postúpili do ekvádorskej provincie El Oro.