Both sides had lost their previous two PNC matches, but it was the Tongans who held on for victory at Lautoka's Churchil Park.
Tonga were blown off the park last week 41-7 by a speedy and physical Japan team, and in the opening stages of Friday's match it seemed they had taken a leaf out of the Brave Blossom's book, racing away to a 19-8 half-time lead through tries to outside backs David Halaifonua and Viliami Lolohea and new centre Malietoa Hingano.
