Lomano Lemeki and Kotaro Matsushima scored second-half tries to ease Japan to a 34-17 win over Italy in Oita.
The visitors took the lead when Tiziano Pasquali touched down but Amanaki Mafi and Kenki Fukuoka registered tries converted by Yu Tamura, who added a penalty.
Braam Steyn's converted try kept Italy within touching distance at 17-14 at half-time before Tommy Allan split the posts to drag the Azzurri level.
But Tamura re-established Japan's lead soon after and then added the extras when Lemeki and Matsushima crossed the whitewash as the hosts eventually cruised to victory.