Jon Bon Jovi had to hit the brakes on his Madison Square Garden show Thursday night ... abruptly ending his set due to an illness ... and promising fans he would make it up to them.

Video of the legendary rocker is going viral online ... showing the moment he tells fans he can't continue the show.

Bon Jovi says he can't continue and needs to cool it ... and he tells fans if they hold on to their ticket stubs, he will make sure they get the performance they deserve at a later date.

With that, Bon Jovi walks away from the microphone and hugs his bandmates before leaving the stage entirely.

A rep for the rocker told PEOPLE, "Jon Bon Jovi spoke from stage and told fans he has been battling a sinus infection which led to the show's early ending. ... As part of the Bon Jovi residency at Madison Square Garden, Jon has said numerous times that it has been a joy to return to live shows for the band. Updated information will be available shortly."

Bon Jovi's touring again after a long hiatus following a serious vocal cord issue that required surgery. This was just the eighth show of his Forever Tour.

Unclear when Bon Jovi will reschedule ... guess fans will just have to keep living on the prayer that he'll be back soon enough.