Ilia Topuria and Paddy Pimblett -- two rising stars in the UFC -- threw punches and bottles in a wild hotel lobby altercation ... and it was all over an offensive tweet.
The skirmish went down just days before UFC Fight Night in London ... where Topuria is slated to fight Jai Herbert, and Pimblett is set to face off against Rodrigo Vargas.
But it was Topuria vs. Pimblett on Tuesday ... as the 11-0 Georgian fighter confronted him for crossing the line in a Twitter exchange last year.