A Yu Tamura-inspired Japan thrashed Tonga 41-7 in Osaka on Saturday to make it two wins from two in the Pacific Nations Cup as they continued their stellar preparations for next month's Rugby World Cup. The result moved Japan to the top of the Pacific Nations Cup standings and sets up a competition decider against the United States in Suva next weekend, following the Eagles 13-10 win over Samoa earlier on Saturday. Despite having winger Kotaro Matsushima sin-binned after four minutes, Japan dominated from the start in defense and attack, running in three tries to hold a 21-0 hafltime lead. Two Tongan-born players, number eight Amanaki Mafi and prop Asaeli Ai Valu, were among the scorers, as the Japanese proved more physical than their Pacific Island opponents. Center Tim Lafaele scored the third try after 30 minutes, following a dummy from the brilliant Tamura. Tamura then added three points with a penalty shortly after half-time, before Tonga finally got on the scoresheet after 56 minutes when lock Leva Fifita went over following a period of sustained Tongan forward pressure. However, two late tries from Matsushima and substitute Kenki Fukuoka saw Japan wrap up a comprehensive victory. Flyhalf Tamura, who supplied two of the Japanese tries, was also perfect with the boot, scoring 16 points. Saturday's result comes after Japan's 34-21 win over Pacific Nations Cup holders Fiji in Kamaishi last weekend as Jamie Joseph's side continue to excel in their World Cup preparations. Japan, Asia's first Rugby World Cup hosts, have two more matches before the tournament opener against Russia in Tokyo on Sept. 20. Following the United States clash on Aug. 10, Japan have a final World Cup warm-up against South Africa on Sept. 6. — Reuters