50 Cent Throws Star-Studded 'Fightland' Premiere With Surprise Performances

50 Cent doesn't do low-key ... and he proved it by turning the premiere of his new STARZ series "Fightland" into a full blown concert and celebrity packed celebration ... and we have it all on video.

The rapper and executive producer hosted Tuesday night's premiere at the Jazz at Lincoln Center in New York, where he welcomed the crowd and told them they would quickly find characters to root for and others to root against.

After the screening, 50 took the stage inside the Rose Theatre for a surprise performance ... rapping some of his biggest hits, including the "Fightland" theme song, before closing with "Hate It or Love It."

Fif also brought out Sleepy Hallow, Rich the Kid and A Boogie ... sending the audience into a frenzy.

The premiere was packed with familiar faces ... including Sherri Shepherd, Ari Melber, LaLa Anthony, Naturi Naughton-Lewis, Wendell Pierce, London Brown, DJ Envy, Tristan Mack Wilds and Tony Yayo.

But the celebration didn't end there.

The party moved to PH Live, where the after-party morphed into another surprise concert as 50 reunited with Uncle Murda, Tony Yayo and Sleepy Hallow for more performances.

50 also hit pause on the music to surprise his longtime publicist, Amanda Ruisi, founder of AKR Public Relations, with a birthday celebration.