Delenn Saves Babylon 5

"Severed Dreams". After declaring independence from EarthGov in the wake of President Clark's coup d'etat, Babylon 5 and its allies have barely defeated two EarthForce destroyers sent to capture the station, when three more ships arrive. At that moment, Delenn arrives with a flotilla of far superior Minbari Sharlin-class War Cruisers, and issues the warning, "Only one human captain has ever survived battle with a Minbari fleet. He is behind me. You are in front of me. If you value your lives, be somewhere else." The attackers promptly retreat.

Example of:
The Cavalry