The 33-year-old, who rides for the Ineos Grenadiers team, on Friday won the 13th leg of this year's race, crossing the finish line well ahead of the chasing pack.
Belgium’s Maxim van Gils came home second, and Slovenia’s Tadej Pogačar, the overall race runner-up, finished third.
Kwiatkowski completed the 137.8-kilometre route from Châtillon-sur-Chalaronne to Grand Colombier in the Jura Mountains in eastern France in 3 hours 17 minutes and 33 seconds.
This marked his second Tour de France stage triumph after he won stage 18 in 2020 and the seventh time in history that a Polish rider took a stage victory in the annual race.
Zenon Jaskuła claimed the first ever Tour de France stage win for Poland and finished third overall in the race in 1993.
In 2014, Rafał Majka won two of the stages and became the race’s fastest climber. He followed up with a stage win in 2015 and best climber title in 2016.
In 2017, Maciej Bodnar won the Marseille time trial stage to become the third Pole to win a Tour de France stage.
Kwiatkowski in 2020 became the fourth Pole to claim a Tour de France stage win.
Kwiatkowski, the 2014 world road race champion, won the 2018 Tour de Pologne, Poland’s largest cycling race.
In March 2018, he won the weeklong Tirreno-Adriatico race in Italy.
Last year, the Pole won the Amstel Gold Race in the Netherlands for the second time in his career.
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Source: PAP, Eurosport