Welsh pair Andrew Selby and Fred Evans secured hard-fought wins before Joseph Joyce sealed matters with a stunning victory over WSB champion Filip Hrgovic at York Hall.
Croatian Hrvoje Sep gave the Arlans an early lead with a points triumph over Swede Babacar Kamara in the light heavyweight (80-85kg) contest, but the hosts went on to claim the next four bouts to clinch the match 4-1.
First Britain's Samuel Maxwell edged Kazakhstan's Yerzhan Mussafirov in the lightweight (57-61kg) meeting to even things up.
Welsh southpaw Evans, Olympic welterweight silver medallist at London 2012, then battled past Kazak Miras Bairkhanov in the middleweight (68-73kg) bout by split decision to get the Lionhearts ahead, before Selby made sure of the win by seeing off debutant Meirbolat Toitov in the bantamweight (50-54kg) showdown.
Joyce then added the gloss to the result by maintaining his unbeaten record with a superb triumph over Hrgovic, one of the division's top boxers, in the heavyweight (+91kg) finale.