Gary Payton Has 50th Birthday Booty Bash at Vegas Club

Gary Payton spent his 50th birthday smackin' a whole lotta butt -- and TMZ Sports has the video.

The NBA Hall of Famer celebrated his half-centennial at a raging nightclub in Vegas -- surrounded by a bunch of hot chicks in thongs and pasties.

They grinded on Gary. He danced and threw money. At one point, he handed out some spankings. Good times had by all.

Oh, yeah ... there was cake too, along with the cakes. But, let's be honest, no one gave a crap about that.