Chris Brown Sued For Alleged Nightclub Beatdown in London

Chris Brown beat the hell out of a man at a London nightclub, and his injuries were so bad he ended up in a hospital ... this according to a new lawsuit.

The singer is being sued by a man named Abe Diaw, who claims Chris smashed him over the head with a bottle of Don Julio 1942 tequila back in February at TAPE nightclub in England.

In the lawsuit, obtained by TMZ, Diaw claims Chris wielded the tequila bottle like a weapon as he pummeled Diaw over the head with "crushing blows."

The guy claims he was knocked unconscious but says that didn't stop Chris from continuing the attack ... he says CB ruthlessly stomped on him as he lay passed out on the club floor.

In the docs, Diaw claims he had to be hospitalized as a result of his alleged injuries ... which he says include cuts on his head and torn ligaments in his leg.

Chris' accuser says there's surveillance footage of the whole thing ... and he says cops in London have the alleged beatdown video. Diaw claims he can identify Chris in the footage and claims CB is a fugitive in the United Kingdom as a result of the alleged incident.

And, get this ... Diaw claims he's known Chris for at least seven years and thought Chris was coming up to hug him at the club when Brown instead allegedly struck him three times with the tequila bottle.

Diaw says his injuries may be permanent and he's suffering serious emotional distress and trauma. He's suing Chris for damages.