Yes, there were other moments, but the writer/director of Parasite won a ton of awards and it was cool and he's the best.
But the cutest and purest and most wonderfulest part of the entire night was during one of Bong Joon-ho's many acceptance speeches. While his cowriter Han Jin-won was saying his thank yous, Bong Joon-ho was having a private moment with his Oscar.
Just the two of them. They look at each other, and Bong Joon-ho smiles.
He holds his little gold statue and inside is (probably) screaming, "HOLY SHIT, YES!!!"