FRANCE'S forwards know they simply have to stop Wales' mobile pack from dictating the game in tomorrow's semi-final, or risk getting overrun.
France have talented, experienced forwards of their own, but they do not have the same speed and overall mobility of the Welsh.
Edging the scrum battle will be crucial to France's chances of winning through to their third final.
France must prevent the flow of balls to Wales' destructive backline, which boasts the brutal running of centre Jamie Roberts, the playmaking of James Hook and the clinical finishing of veteran winger Shane Williams.
Prop Nicolas Mas is looking forward to the challenge of tiring Wales out. Having played his only match of the tournament so far in the quarter-final win against England, he should have plenty of energy.
"We need to be efficient up front, make them run a lot, wear them out in the scrums and the maul to prevent them from being everywhere on the field," Mas said. "They have a good scrum, they're good at the put-in and release the ball very quickly."
"We (the forwards) are not really meant to think. We're there to be efficient and to give good ball to the backs," he said. "They have a combative team and never give up."
Adam Jones and Gethin Jenkins will take on Mas and Jean-Baptiste Poux in what promises to be an even contest between two sets of props.
French locks Pascal Pape and Lionel Nallet also face a hard task against Alun-Wyn Jones and Luke Charteris.
The back-row contest could end up being the most decisive, however.
France boasts No8 Imanol Harinordoquy and flanker Julien Bonnaire - both were outstanding against England - as well as captain Thierry Dusautoir, a fierce tackler who will be trying to keep Hook in check.
But with No8 Toby Faletau, Sam Warburton and Dan Lydiate, Wales have a quicker back-row and could cause damage if the French can't protect their ruck ball.
"Their front five are very mobile, their second-rowers are good in the lineouts. They're a little more mobile than us," Pape said. "It's up to us to make them run a bit less. We have to rob them of the ball and impose our authority on the game."
Wales: L Halfpenny; G North, J Davies, J Roberts, S Williams; J Hook, M Phillips; G Jenkins, H Bennett, A Jones, L Charteris, A-W Jones, D Lydiate, S Warburton (capt), T Faletau. Reserves: L Burns, P James, B Davies, R Jones, L Williams, S Jones, S Williams.
France: M Medard; V Clerc, A Rougerie, M Mermoz, A Palisson; M Parra, D Yachvili; JB Poux, W Servat, N Mas, P Pape, L Nallet, T Dusautoir (capt), J Bonnaire, I Harinordoquy. Reserves: D Szarzewski, F Barcella, J Pierre, F Ouedraogo, F Trinh-Duc, JM Doussain, C Heymans.