Sacramento Kings star Ty Lawson was partying his face off with teammates at a Vegas club Thursday night before missing a team flight on Friday morning ... TMZ Sports has learned.
Lawson hit up Drai's nightclub along with Ben McLemore and Willie Cauley-Stein and boxer Adrien Broner ... and you can see in the video, they seemed to be having a great time.
Problem is ... Lawson missed the team flight to Kentucky for an exhibition game the next day and Kings' honchos are reportedly demanding an explanation.