Shareef O'Neal ain't lackin' confidence ... telling TMZ Sports he'd dominate LaMelo Ball if the two face off on the court.
Shareef (17) and Melo (15) are two of the biggest stars in high school hoops -- so, when we saw Shaq's kid at LAX, we had to ask how a showdown with the youngest Ball bro would go down.
FYI -- Shareef is bigger than 'Melo at 6'8'' (Ball is 6'3") ... but Ball's a proven scoring machine, once dropping 92 points in a single game.