The fight took place as part of the UFC 254 tournament in Abu Dhabi on "Fight Island".
The Russian fighter performed a choke hold in the second round, and Gatji surrendered.
For Nurmagomedov, this is the fourth successful title defense in the UFC.
RT conducted a text broadcast of the fight for the title of champion of the Absolute Fighting Championship in lightweight between Nurmagomedov and Gatji.
Previously, Robert Whittaker defeated Jared Cannonier at UFC 254.