The good friends took down Colombian third seeds Juan-Sebastian Cabal and Robert Farah 7-5, 6-4 to reach set an all-unseeded final against Kevin Krawietz and Andreas Mies.
Frenchmen surge into doubles final
Chardy and Martin thrill home fans with upset of third seeds to set final clash with German duo
Chardy and Martin will look to follow in the footsteps of compatriots Nicolas Mahut and Pierres-Hugues Herbert, who sparked raucous celebrations on Court Philippe-Chatrier last year when they hoisted the trophy.
It is the fourth time in seven years an all-French team is through to the men’s doubles final in Paris.
In what could have been a Tokyo 2020 Olympic semi-final line-up, the French beat the Colombians, and Germans Krawietz and Mies saw off Argentine pair Guido Pella and Diego Schwartzman 7-5, 6-3.
But Mertens and Sabalenka proved too strong for Lyudmyla Kichenok and Jelena Ostapenko 7-5, 6-2, ensuring Mertens would hold onto top spot.
The sixth seeds complete the women’s doubles semi-final line-up and will face second seeds Timea Babos and Mladenovic for a place in the final.
In mixed doubles semi-finals, Latisha Chan and Ivan Dodig upset top seeds Nicole Melichar and Bruno Soares 6-2, 6-1 to set a final showdown with No.2 seeds Gabriela Dabrowski and Mate Pavic.
Dabrowski and Pavic narrowly held off Nadia Kichenok and Aisam Ul Haq Qureshi 6-7(4), 6-1, [10-8].