UFC Fighter Ailin Pérez Twerks In Opponent's Face After Submission

Ailin Pérez may not have gotten her opponent in a rear naked choke during her UFC fight Saturday ... but, she certainly got her own rear working -- twerking in her opponent's face after winning by submission.

The bantamweight fighter hopped in the Octagon at UFC Paris against Daria Zhelezniakova ... and, she quickly dominated her opponent -- getting DZ to tap out in the first round.

Perez jumped to her feet ... and, ya gotta watch as she swished her booty back and forth right in front of her red-faced opponent, still gasping for breath.

As Daria slowly gets to her feet, Ailin keeps her backside moving ... doubling down on the W with the movement of her derrière.

Perez wasn't done twerking either ... throwing it back once more after the ref raised her arm in victory -- while her team pretended to throw money on her.

Apparently, this is sort of a thing BTW ... the fighter pulled a similar thing back in June when she defeated Joselyne Edwards by decision back in June -- so, this is sorta Perez's signature victory dance.

While she may look stoked now ... Ailin had a bit of a difficult time before this fight -- missing weight at the weigh-in earlier this week and becoming visibly emotional before an official led her off the stage.