This is the GREATEST reaction to Damian Lillard's game-winning shot Tuesday night -- his sister storming the court while screaming "That's my brother" ... and she got the whole thing on video!!
La'nae Lillard was sitting courtside at the Moda Center in Portland to watch the Trail Blazers take on the OKC Thunder in Game 5 of their NBA playoff series.
And almost like she KNEW Dame was gonna sink that buzzer-beater, she busted out her phone and began recording the whole thing to her IG story.
Dame shot. Dame scored. La'nae went WILD -- rushing over to the celebratory pile in the middle of the court while yelling at the top of her lungs, "THAT'S MY BROTHER!