Injured LeBron James Attends Son's Playoff Game, Bronny Goes Off!

LeBron James' foot injury didn't stop him from going to Bronny's playoff game on Thursday night ... and he's sure as hell glad that was the case, 'cause he got to see his kid go OFF in a thriller!!

The young James and his Sierra Canyon squad went up against sixth-seeded Etiwanda in Chatsworth, Calif. in a CIF State regional quarterfinal game ... and Bronny had quite the night.

The 6-foot-3 guard -- who was just selected to the McDonald's All-American Game -- scored 21 points from all over the court ... and even got a chance to throw down a huge dunk in front of dad.

LeBron was front and center to watch it all -- cheering his face off -- while making sure to keep his injured foot protected by a huge walking boot.

Riding Bronny's performance, the Trailblazers ultimately won the important game, 61-55 -- and LeBron couldn't have been happier about it afterward.

"Bronny you were SPECIAL tonight kid!!" James said via Twitter. "Keep going! AlwaysProudDad"

Bronny's S.C. team will now head to the semifinals to face Bishop Montgomery, the tourney's No. 2 seed, on Saturday.

Lucky for 'Bron, the Lakers are off on that date ... so, it's more than likely he'll be courtside for the big game then, too.