Tunisia got a boost before their World Cup opener against Russia on 5 June, as they beat Japanese second-division side Cerezo Osaka 3-0 in a warm-up on Thursday.
Khaled Badra opened scoring for the Tunisians in the 22nd minute, with Adel Sellimi and Riadh Jelassi completing the rout.
It is their first win in a friendly match since arriving in the Far East.
Before the win, Tunisia were beaten by two Japanese club sides and lost 2-1 to Denmark.
Since the team arrived in Japan, Ammar Souayah, Tunisia's manager has been forced to defend their poor scoring record.
"Travelling far distances to play the friendlies adds to the overall exhaustion from travelling to the Far East and adjusting to the time difference," he said.
Souayah added that, as the team had now adjusted, Tunisia fans could be more optimistic of a credible World Cup performance.