Stephen Jones must play at fly-half against Australia next Saturday, says Wales great Jonathan Davies.
Jones sparked a second-half revival for Wales against Canada
Jones came on off the bench on Sunday to help inspire Wales from 9-17 down to eventually win 42-17 against Canada.
"I've always said that James Hook should play, but Stephen Jones showed what a good player he is," Davies told BBC Wales' Scrum V programme.
"We needed his experience on the pitch and when he came on he gave us direction and the tactics changed."
It was Jones' first game since the groin injury that almost ruled him out of the entire 2007 World Cup campaign.
There had been doubts over his fitness, but the 29-year-old Scarlets fly-half looked rejuvenated and fresh as he took on the Canadians after replacing Hook.
"Jones and Hook are both different players, but Stephen showed exactly what he is capable of and I think he has played his way back into the team," added Davies.
"He dictated the play when he came on and that is what we need from a number 10.
"We shouldn't write James Hook off and I'm sure he can have a big impact on the game off the bench, but against a side like Australia we need Stephen Jones' experience."
Gareth Jenkins will name his team for Saturday's crucial Pool B match in Cardiff at Thursday lunchtime.
Jonathan Davies was speaking on BBC Wales' Scrum V programme.