The duo on Saturday saw off the German pairing of Constantin Frantzen and Hendrik Jebens 6-4, 6-4 in the championship match to claim their third title together and second of the season.
The clash at the hard-court tournament in northeastern France lasted 73 minutes, Polish state news agency PAP reported.
Zieliński and Nys in May won the men’s doubles at the Italian Open clay-court tournament in Rome.
In January, the two reached the final of the Australian Open men's doubles in Melbourne.
Last year in Metz they secured their first win as a doubles team.
Jan Zieliński and Hugo Nys. Photo: PAP/Marcin Cholewiński
Poland's Zieliński in 2021 won the Metz Open doubles with countryman Hubert Hurkacz.
Jan Zieliński. Photo: PAP/Piotr Nowak
(gs)
Source: IAR, PAP