The duo defeated home favourites Sadio Doumbia and Fabien Reboul 6-7, 6-2, 10-2 in the semifinals of the hard-court event in northeastern France on Friday.
Zieliński and Nys will face Germans Constantin Frantzen and Hendrik Jebens in the championship match on Saturday.
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.
(gs)
Source: IAR, PAP