Tristan Thompson celebrated the Cleveland Cavs big win over Brooklyn Nets Wednesday night by taking it back pre-Khloe ... when he was a single dude.
Tristan and teammate Jae Crowder hit up Cleveland hot spot Magnolia nightclub at 2am. Rapper PARTYNEXTDOOR was also there but laying low until Tristan blew his cover.
The guy onstage at the time, rapper Choochie Flvco, didn't seem to mind the Canadian rapper taking over with "Recognize," which Tristan told everyone was one of his faves pre-Khloe.
FUN FACT: PARTYNEXTDOOR briefly dated Kylie Jenner, so doesn't look like there's any bad blood with Tristan hanging with a Kardashian ex.