After ending the season in 18th spot on the table with 34 points from 38 games, the Mustards escaped relegation by a whisker but could not secure an automatic stay in the French top-flight.
They lock horns with French Ligue 2 side Lens for a lifeline to continue their stay in the elite French division.
The first leg of the encounter ended in a 1-1 stalemate at Stade Bollaert-Delelis on May 30.
Antoine Kombouare’s men then sealed their place in Ligue 1 next season with the Tunisia international leading the way.
Sliti opened the scoring in the 28th minute after he was set up by Wesley Lautoa before Jean-Kevin Duverne equalised for the Blood and Gold.
In the 70th minute, Wesley Said restored the lead for the Mustards off Sory Kaba’s assist before Sliti sealed the victory in added time.
Sliti featured for the duration of the game along with Central African Republic defender Cedric Yambere.
The Cartage Eagles are paired alongside Angola, Mali and Mauritania in Group E.