Jhene Aiko brought her performance to a screeching halt as soon as she noticed something terribly wrong in the crowd -- one of her fans having a seizure.

The scary incident went down Monday night at Buckhead Theatre in Atlanta where Jhene was headlining. She was in the middle of a song when she stopped the show and frantically called for a medic.

The video shows medics carrying out the fan, who was still violently shaking.

Jhene was classy and poised before resuming the concert, and even warned fans about strobe lights onstage ... which can trigger seizures.