France coach Herve Renard has warned his team they must keep their focus or it "can all come tumbling down" after being stunned by an early goal from Panama and leaking another two late on.

Women's World Cup debutants Panama silenced the world number five with a strike in the first minute of their Group F clash in Sydney on Wednesday before France woke up to race 5-1 ahead.

But with a last-16 place secure, France eased off and were punished twice more by a team ranked 47 places lower.

Renard accused his team of looking for "an easy game" and said they did not exist at a World Cup.

"My girls weren't playing as they should have been playing and, collectively, we were looking for the easy solution, the easy game, forgetting that in a World Cup, you need to show respect," Renard said after the 6-3 win.

"Everything that you've built up can come tumbling down in a matter of seconds."

France rested captain Wendie Renard, and when her replacement Grace Geyoro came off among a slew of substitutions to give other players a chance they lacked leadership.

Renard said it was a wake-up call for those who came on, including Laurina Fazer, Amel Majri and Viviane Asseyi.

"We were 5-1 up, with the game in the bag ... you see this often in football. It was poor attitude from the girls for a few minutes," he said.

"This shows the ones who are hoping to be part of the starting 11, they need to work a little bit harder and pull their socks up, because what I saw maybe wasn't good enough."

France will face the runners-up from Group H in the last 16 on Tuesday -- possibly two-time champions Germany.

Paris FC attacking midfielder Clara Mateo said the defensive mistakes must be fixed or they could be in trouble.

"We were quite consistent offensively because we scored six times," she said, with Kadidiatou Diani hitting a hat-trick.

"However, we conceded three goals so we will have to check what happened to fix our defensive mistakes.

"We know that in the knockout stage, it could be fatal so we need to improve the defensive aspect and keep on scoring goals."