Zac Efron watched his little brother soaring and flying in the ballroom.

And as Dylan Efron tangoed with dance pro Daniella Karagach during the Dancing With the Stars semifinals Nov. 18, he couldn't be more thrilled to have the High School Musical star cheering him on.

"It meant everything," the Traitors alum told E! News' Will Marfuggi alongside Daniella after their performance. "I grew up watching him do stuff like this. So, the fact that he's now watching me do this is crazy to me."

He's so grateful to see how proud Zac, 38, is of him, adding, "It means the world to me."

Indeed, as Dylan and Daniella hit the dancefloor to perform their routine during the Prince -themed episode, Zac was all smiles with their little sister Olivia , 5, in

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