Danish headbutt

The only way to do a headbutt with a crate of beer in each hand.

Swede 1: "Han kom hit med en ölfat i varje hand, och han slog mig rakt ut." ("He came over with beerkeg in each hand and he knocked me right out.")

Swede 2: "Hur gjorde han det?" ("How did he do that?")

Swede 3: "Måste ha varit den berömda danska skallning antar jag." ("Must have been the renowned danish headbutt.")