Stitches: Parking Lot Beatdown ... First Video of K.O. #2

Stitches should change his name to Punches -- the rapper got slugged less than 24 hours after The Game's manager laid him out, and now there's video.

A source close to the rapper says the people delivering this smackdown were all current or former members of Stitches' crew. We're told one guy thought Stitches was setting him up to get robbed -- so he arranged a meeting last Saturday at a Florida barbershop.

When Stitches showed up, it was on. You can see in the video ... he tried to run, but ended up catching a few solid shots to the face. Remember, he was just coming off a night in jail and the K.O. at the hands of Wack 100, Game's manager.

No one brags about an ass whupping better than Stitches.