LSU guard Flau'Jae Johnson went from scoring buckets to dropping bars after the Tigers' national championship win on Sunday ... leading the team's celebration by performing her very own rap song!!
TMZ Sports has learned ... the freshman baller took over the mic at the Westin Hotel conference room in Dallas after the Tigers whooped the Iowa Hawkeyes, 102-85 -- and it was a party for the ages.
You can see Johnson -- who scored 10 points in the championship game -- on stage with her teammates, reciting the lyrics to her "BIG 4" track that dropped just a few months ago.