BigXThaPlug and Crew Fight Fan Who Threw Water While He Was Performing

12:05 PM PT -- In an incident report obtained by TMZ ... the unidentified victim says he was holding a bottle of water when he was pushed from behind at the show, splashing water onto the stage, dousing BigXThaPlug. The victim says BigX looked at him "with a real mean face," prompting someone from the rapper's team to punch him.

The victim told cops other members of the crew allegedly jumped off the stage and struck the victim as many as 50 times over 5 minutes as he covered up in a fetal position on the floor, and he says he was kicked and stomped ... all requiring hospitalization for cuts and bruises. The victim claims 2 gold chains and a pair of $2,000 Cartier sunglasses were stolen during the melee.

BigXThaPlug and his crew cleaned a fan's clock during his sold-out "Take Care" tour, and TMZ Hip Hop has their showdown -- and ensuing brawl -- all on camera!!!

Multiple sources tell us one particular guy in the crowd was heckling BigX during the rapper's Seattle stop on Dec. 8 ... obnoxiously causing a scene as the "Amar" hitmaker was onstage.

A line was drawn when the heckler threw water at BigX ... and the top-heavy rapper and his crew hopped off the stage to defend themselves.

BigX has a hit track warning the world not to mess wit' "Texas" -- and as you can tell by the guy's bloodied face, he and his crew meant business!!!

We're told the music stopped briefly as police got things in order, but BigX got back onstage and the show went on without a hitch ... as did the last 2 tour spots several days later.

He had a monster year and his 2025 is already shaping up nicely with a country EP collab with Shaboozey, Post Malone, Morgan Wallen and others.

Interestingly enough, BigX kicked out a pair of fighters at his L.A. show a few days prior to this Seattle gig ... his show, his rules!!!

Concerts can be a gauntlet for artists sometimes ... Zach Bryan, Bebe Rexha and Cardi B have all been down this road before.