Master P's son, Mercy, balled out with 18 points in a huge playoff win over Sierra Canyon on Tuesday ... officially bringing Bronny James' high school basketball career to an end.
Sherman Oaks Notre Dame -- the #1 seed -- easily handled S.C. in the CIF Southern California Division 1 Regional, 80-61 ... punching its ticket to the state finals later this week.
There were some big names in the crowd as N.D. secured the win ... including Mercy's rap legend dad and French Montana.
Notre Dame's Caleb Foster -- who's committed to play for Duke -- dropped 28 points in the win ... with Isaiah Elohim, a Kansas and Illinois recruit, adding 16 for Sierra Canyon.
Mercy -- a junior -- has a bright future on the hardwood ... and is set to play college ball at Houston.
Bronny had 10 points in his final high school game ... but his NBA superstar dad, LeBron, was not in attendance for the contest (the Lakers had a game).
All eyes are on Bronny now ... as he's yet to announce whether he's going to college, heading to Europe or joining the NBA's G League.