SPOILER WARNING: The following article contains spoilers for The CW's big DCTV crossover event, "Invasion!"

In a crossover event just filled with dream team-ups, Easter eggs, and teases of what lies ahead for our favorite heroes, the best fan service-style moment occurred during the final few minutes of "DC's Legends of Tomorrow's" closing chapter.

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At the heroes' invitation only after-invasion party, viewers finally got to see what many had been hoping for since the crossover began; the characters from four different shows out of costume mingling, joking and generally having a good time among friends. Oliver and Kara finally bonded, Barry and Oliver considered revising their arrow-vs-speed challenge for a third time, and Cisco provided Supergirl with a dimension-hopping gizmo, opening the door to the next team-up.

But the best moment came following a brief interaction between Ray, Felicity and Kara. While Felicity commented on how similar she and Kara are ("It's like looking in a mirror."), the Ray's comment stole the show -- and perhaps the entire crossover.

"Yeah - you know what's funny? She really kinda looks like my cousin," Ray said quietly as Kara walked away. It's a quick, subtle and genuinely fun reference to his stint as the Man of Steel in "Superman Returns," made all the more humorous by the "Wait -- what...?" look Routh and Emily Bett Rickards share right after.

Airing Thursdays at 8 pm ET/PT on The CW -- until January 24, when it shifts to Tuesdays at 9 pm -- "DC's Legends of Tomorrow" stars Arthur Darvill as Rip Hunter, Brandon Routh as the Atom, Victor Garber and Franz Drameh as Firestorm, Caity Lotz as White Canary, Maisie Richardson-Seller as Vixen, Dominic Purcell as Heatwave and Nick Zano as Citizen Steel.