A frustrated Jacques Brunel said France have to "go back to basics" after stumbling past Tonga to reach the Rugby World Cup quarter-finals.
Les Bleus won 23-21 on Sunday to set up a Pool C decider against England next week but it was a performance blighted by turnovers and handling errors in Kumamoto.
The impressive Alivereti Raka, who scored a try and set up another, helped France into a 17-0 lead, only for Tonga to put up a brave fightback.
Head coach Brunel cut an exasperated figure when addressing the media after the game and says France will have to put in the hard work on the training ground.
"We want to play better so we need to train more," he said.
"We wanted a bigger scoreline but because of handling errors we were not able to achieve that. Therefore, I guess, we need to go back to basics.
"We tried many different things which didn't work.
"I'm dissatisfied, like the players who are frustrated. We did attack, had clear opportunities to score quite heavily in the first half, but we made handling errors."
On facing England next time out, Brunel added: "Of course, it's a formidable opponent. We know the difficulty that awaits us, but I think it will be a good meeting before our quarter-final."
Tonga famously defeated France in the 2011 pool stages and head coach Toutai Kefu rued a slow start on this occasion.
"We haven't started games well and it's definitely an issue for us," he said. "Maybe we warm up too long, I don't know.
"But I'm definitely proud of what happened after that – the way they stuck in there and put us in a position to maybe win.
"I'm always proud of the boys, the sacrifices they make just to turn up and endure what they endure on tour."