Samoa have opened their World Cup campaign by crushing France in a 78-4 win that gives an early boost to the Pacific nation's hopes of reaching the knockout stages.

In a 14 tries-to-one victory in which centre Stephen Crichton kicked 11 goals and Melbourne flyer Sua Fa'alogo crossed four times, the Samoans barely worked up a sweat at CommBank Stadium in Sydney on Friday.

Taking on a French side mostly made up of Super League players, the star-studded Samoa team raced out to a 28-0 lead inside 20 minutes.

The only blemish for coach Ben Gardiner was the sight of Brisbane winger Deine Mariner going off in the first half with a suspected injury. 

And while they had lapses of discipline and concentration with the result sewn up - France scored their sole try through winger Guillermo Aispuro-Bichet - the heavy win will increase Samoa's points differential and their hopes of making it to the semi-finals.

One of Samoa, England or Tonga will miss the knockout stages as a result of the new tournament format, in which the top two teams from across group B and group C make it to the last four.

Samoa face Papua New Guinea in Port Moresby next week before concluding their pool games in an all-Pacific match-up for the ages against the Tongans.

The Kumuls on home soil and Tonga in Sydney will provide a much sterner test than the French, who were left for dead in a blistering opening quarter. 

Mariner scored the opening try for the Toa in the third minute soon after his father Lapi had sung the country's national anthem that brought stars including Jarome Luai and Spencer Leniu to tears. 

Benaiah Ioelu, Jermaine McEwen, Fa'alogo, and Hamiso Tabuai-Fidow all crossed in the next 15 minutes as the French defence was cut to shreds. 

Aispuro-Bichet briefly stemmed the bleeding before Fa'alogo went in again just before halftime to make it 34-4 at the break.

The French had little resistance in the second period, with Fa'alogo adding two more while Crichton, Chanel Harris-Tavita, Shawn Blore, Izack Tago, Francis Molo and Ioelu all went over.