Fiji will join England, Australia and Wales in Pool A at next year's World Cup after they crushed the Cook Islands 108-6 in Lautoka on Saturday.
Despite being 6-5 down after 27 minutes in the play-off for a place at 2015's showpiece, Fiji settled and cut loose for the next 50 minutes.
Nemani Nadolo scored three while Matuisela Talebula, Adriu Delai, Nikola Matawalu and Timoci Nagusa all picked up a brace apiece.
Fiji's opening game will be against host nation England at Twickenham on 18 September.