Germany cantered to victory in its Group F opener in Christchurch, leading 6-0 at half-time before scoring twice more in the second half.
Hany Mukhtar (three), Niklas Stark (two), Marc Stendera, Grischa Promel and Marvin Stefaniak were on target for Germany, with Iosefo Verevou netting a consolation for Fiji just after half-time.
In the group's other game, Honduras edged out Uzbekistan 4-3 in Christchurch.
Brazil came from 2-1 down to defeat Nigeria 4-2 in Group E.
Gabriel put Brazil ahead early but Nigeria was in front by the 28th minute thanks to goals from Success Isaac and Musa Yahaya.
Judivan brought Brazil back on level terms, however, with Boschilia and Judivan's second easing their side to victory.
Hungary went top of the section after it romped past Korea DPR 5-1 with Bence Mervo snaring a hat-trick.
