After knocking the bar in his first two attempts at the height, the Olympic champion cleared the mark with room to spare on the third try, letting out a cheer as the crowd went into a frenzy of celebration.
He had barely touched the mat before a spray of sparklers went off and meet director Renaud Lavillenie, the Olympic champion in 2012, ran to embrace him.
Duplantis had the competition won already when he cleared 6.01 metres on the first try, as Australian Kurtis Marschall (25) finished second with a 5.91 metres leap while the Netherlands' Menno Vloon (28) took third.
He set the previous record on his way to winning gold at the World Championships in Eugene, Oregon, in July.
Saturday's effort marks the sixth world record of his career and the 60th time that he has cleared six metres or higher.