Despite bidding for just two wins to see them safely through to the semi-finals having won the home quarter-final leg 4-1 at York Hall, it was a completely different story in Foro Polanco.
Commonwealth champion Sean McGoldrick got the Lionhearts underway but he was unable to find a way past last season's Individual Championships finalist Elias Emigdio and the home side picked up the first point.
And the Guerreros didn't look back as Sam Maxwell lost his lightweight bout with Juan Romero before Kaupo Arro was defeated by Marvin Cabrera to level the scores.
Babacar Kamara's light heavyweight defeat to Issac Munoz gave the Guerreros the lead before Gerardo Miguel Bisbal beat Uaine Fa to round off a fine evening for the hosts.
While the British Lionhearts' World Series of Boxing debut is over, the Mexico Guerreros now face Kazakhstan - whom Britain overcame in group action at Bethnal Green - in the semi-final.