Opportunity missed for rueful French

France halfback William Barthau concedes his side missed out on a wonderful opportunity to qualify for the knockout stage following their 29-18 loss to Lebanon on Sunday afternoon.

With three teams from Pool A guaranteed a place in the quarter-finals, a win over the Cedars in Canberra would have been enough to all-but secure their passage to the next stage of the competition, but instead they must now upset either Australia or England and hope results go their way.

It's an unenviable position for the world's sixth-best side to be in, especially after they did so well to make the final eight at the 2013 World Cup.

There were positive signs on Sunday with France happy to throw the ball around, however their expansive tactics came back to haunt them with Aurelien Cologni's men completing just 68 per cent of their sets as Mitchell Moses tore them apart at the death to seal Lebanon's maiden World Cup win.

"I think we missed a big opportunity today to qualify for the quarter-finals," Barthau said after the game. 

"We just needed to manage the game a little bit better. There were a few too many errors in the first half that cost us in the last 10 minutes.

"Maybe we were a bit nervous because maybe there was a bit too much enthusiasm at the start. We just forced too many plays and I think we should have just completed our sets to put more pressure on Lebanon."