Montano enters and calls for Cassio to begin his watch; he is surprised to find Cassio drunk and barely able to stand upright. Iago lies to Montano, telling him that this is how Cassio spends every evening. Roderigo laughs at Cassio's drunkenness and Cassio attacks him. Montano tells Cassio to calm down, but Cassio draws his sword and threatens to crack open Montano's head. (Montano, Cassio, Iago, Roderigo, chorus: "Capitano, v'attende la fazione ai baluardi" / "Captain, the guard awaits you on the ramparts".) Cassio and Montano begin to duel, and Iago sends Roderigo to call the alarm. Montano is wounded and the fight is stopped only by the appearance of Otello.