A try-scorer for Leicester Tigers in the Aviva Premiership semi-final and final, back-rower Mafi has started both games in the IRB tournament as Tonga recovered from a 20-18 defeat by Samoa on Tuesday win against Japan in Tokyo.
Tigers team-mate Logovi’i Mulipola has played in each of Samoa’s two fixtures, starting the win over Tonga and appearing as a replacement to gain his eighth senior cap in a 29-26 victory over Fiji.
Tonga’s next game is against Fiji on June 23, while Samoa face host country Japan on Sunday.
Tigers prop Martin Castrogiovanni will have unhappy memories of his return to Argentina in an Italy shirt.
Castrogiovanni was born in Parana in Argentina but moved to Italy as a teenager.
He earned his 86th international cap in the Italy front row as they were beaten 37-22 in the opening match of their summer tour. The Azzurri move on to face Canada in their next game on Saturday.