garry’s posthaven

From the practice of a medieval knight throwing down his metal glove as a challenge to combat.

throw down the gauntlet

1. (idiomatic) To issue a challenge.

   The competing firm threw down the gauntlet by offering a faster product at a lower price.

Did not know what a gauntlet was, but consider it thrown. Faster product at a lower price. That's what I'm talking about. Booyah!