The second bout of UFC 172 at Baltimore Arena featured two lightweights, Danny Castillo and Charlie Brenneman — and it ended with almost as dramatic knockout as the first.

A one-punch knockout ended the night for Brenneman, as Castillo recovered from a slow start to record the KO with a big right hand in round two.

Castillo entered the Octagon about a four to one betting favorite, but it was Brenneman who was the aggressor to begin — hitting several takedowns to surprise the Team Alpha Male product. One stretch in side control saw Brenneman pressuring down hard and hitting knees to the body and arm.

But to begin the second, Castillo absorbed a leg kick, ducked forward, and landed a huge overhand right to end the bout.

An emotional Castillo credited his coaches, including Duane “Bang” Ludwig, after the bout — the night’s first to be broadcast among Fox Sports 1’s coverage of the preliminary bouts.

Danny Castillo defeats Charlie Brenneman by knockout (overhand right) at 0:29 of round two.