LYON, France -- France defeated Fiji 54-17 in a bruising clash at the possible cost of flyhalf Romain Ntamack on Saturday for the showdown with South Africa in Nations Championship rugby.

Ntamack left the match in obvious pain in the 33rd minute with an apparent shoulder injury.

With other main options Matthieu Jalibert, Antoine Hastoy and Thomas Ramos already out injured, France may need a new 10 against the world champion Springboks on Friday in Paris.

Maxime Lucu, one of only two backs on the bench, deputized at flyhalf smoothly and goalkicked superbly but he's normally the scrumhalf backup for captain Antoine Dupont.

France scored eight tries but worked overtime against Fiji’s ferocious defense to grind out a 26-3 lead at halftime. The French blew out the score in style with four converted tries in a madcap last quarter when Fiji also nailed its only two touchdowns.

Fiji also had a flyhalf issue. Initial surprise pick Isikeli Rabitu was a late withdrawal and France-based center Vilimoni Botitu filled in.

Fiji made up for struggles with contestable kicks by forcing errors from the French, who couldn't score until the 15th minute when prop Jean-Baptiste Gros bulldozed over in support of fullback Théo Atissogbe.

A penalty try followed when Fiji lock Mesake Vocevoce collapsed a rolling maul and was sin-binned. In his absence, Fiji kicked a penalty and kept France scoreless.

But then Ntamack was injured in a run short of the tryline that was finished by prop Sipili Falatea, who bumped off an attempted double tackle.

The half ended with winger Aaron Grandidier Nkanang scooping and scoring when his chip wasn't cleanly taken by Botitu.

Fiji didn't concede again until an hour was up when France center Kalvin Gourgues finished lovely handling from a turnover in the Fiji 22. Lucu's first extras made it 33-3.

The try unlocked a six-try spree in the last quarter, with both sides scoring from deep against tiring defenses.

The best of them were Dupont counterattacking from his half, slipping two Fijians and finding Louis Bielle-Biarrey to send Atissogbe clear, and Fiji center Selestino Ravutaumada finishing between the posts a move from their own 22.

Fiji, still winless at 0-4, is in Ireland next weekend.