Tom Brady and Jimmy Kimmel got Ice Cube's back in a big way -- helping the BIG3 co-founder smash another basketball league in a nasty legal war ... TMZ Sports has learned.
The BIG3 had been sued by Champions League -- which promoted itself as a 5-on-5 league comprised mainly of former NBA players and coaches, despite the fact they never played a single game.
CL claimed BIG3 broke agreement which would allow BIG3 players to compete in the other league.