Metta World Peace is un-retiring ... from hip-hop ... and TMZ Sports has video of MWP re-igniting his rap career with a performance at one of L.A.'s hottest clubs.
It went down Friday night at Bootsy Bellows in West Hollywood when Metta and his crew took the stage to perform a cut off his new album "Diamond Wave."
If you think it's a one-off you're wrong ... we spoke to MWP and he tells us he wants to rap full time after his NBA career is over ... and will be doing more club dates like the one at Bootsy's.
BTW -- Metta tells us "Diamond Wave" is his official comeback album even though he dropped one back in March, because according to him he "didn't like" the other one.
Check out the clip and judge his skills for yourself.