A rep for Inn of the Mountain Gods casino in New Mexico -- where the concert took place -- tells TMZ, "During the post-performance party at the property, the intoxicated fan and his group of friends, who were also visibly inebriated, returned and continually attempted to get close to Vince."
The rep says the group followed Vince to the private section where he was chilling with the band.
Thankfully, we're told the group -- hell-bent on revenge -- was intercepted by security ... and the fan was subsequently escorted from the property.
As for what caused the initial fight -- we're told the fan had repeatedly tried to grab at Vince while he was singing on stage ... and Vince eventually got fed up with it.












