The Paris Saint-German forward now has a tournament-leading five goals and the 2018 champions are within three wins of defending their title.
Robert Lewandowski scored from the penalty spot in second-half stoppage time for Poland.
No country has repeated as World Cup champions in six decades — since Brazil achieved the feat by claiming consecutive trophies in 1958 and 1962. Italy is the only other nation to have won two straight, in 1934 and 1938.
France’s quarterfinal opponent will be either England or Senegal.
Andrew Dampf is at https://twitter.com/AndrewDampf