FIJI scored five tries to three to beat Tonga 36-20 yesterday.
Tonga, who beat Australia A last week, were missing some of their more prominent names such as former Wallabies outside back Israel Folau.
Playing in their only home game before the global tournament, Fiji raced into a 19-0 lead after 12 minutes in Lauto ka before Tonga fought back.
Captain Waisea Nayacalevu and Sam Matavesi crossed for early tries but Tonga Tonga closed to within four points following scores from forwards Siua Maile and Halaleva Fifita. But Fiji pushed their lead to 26-15 at the interval when Josua Tuisova scored their fourth try.
Tongan back Kyren Taumoefolau scored his side's only try of the second half before replacement Fijian scrum-half Peni Matawalu scored a late try off the back of scrum pressure.
Fiji face Australia, Wales, Georgia and Uruguay in their World Cup Pool while Tonga have drawn South Africa, Ireland, Scotland and Romania.
