Kylian Mbappe did not perform at his best against Poland despite a second-half brace that helped fire France into the quarter-finals, Didier Deschamps said.

With five goals in Qatar, Mbappe's career tally at the World Cup is now at nine at the age of 23, with only Just Fontaine (13) scoring more for France at the tournament – all of which came in the 1958 World Cup.

Despite his goalscoring exploits, Deschamps stated his belief Mbappe did not have his best performance.

"We know about Kylian. We've already seen him. He speaks on the football pitch," the coach said in the post-match press conference.

"He didn't have his best match tonight, I don't want to accuse him of anything, and he knows that himself. But he can change a match in a moment.

"He's playing with such joy. We want to share those smiles with him. France needed a great Kylian Mbappe tonight, and they got one."

The Paris Saint-Germain striker will share the headlines with Olivier Giroud, who opened the scoring against Poland to become his nation's all-time leading scorer with 52 goals – surpassing Thierry Henry's tally that had stood since 2009.

Giroud was a key member of France's squad in Russia in 2018, although he failed to score and now boasts four goals in Qatar, an impressive return considering he would likely have played a reduced role had Karim Benzema remained fit.

Deschamps hailed Giroud's efforts and impact but acknowledged he may well be surpassed by Mbappe further down the line. The France number 10 already has 33 international goals.

"Olivier has always been an important player. Four years ago he didn't score, but he was a very important player for us," Deschamps said. "There were difficult periods for him in his career.

"Today we're seeing his quality. He's often criticised but has managed to remain strong, mentally strong. It was a very difficult record, because it was Thierry Henry before him.

"There's a guy next to me [Mbappe] who might break it one day. To score so many goals at international level is an incredible achievement."