Opening Salvo stops attack.
When using Opening Salvo, it'll do the 3 damage to the defender chosen. If the defender has more then 3 life the attack will proceed. If the defender has 3 or less life and is killed by the Opening Salvo, the attacking creature stops it's attack, does no damage, and is stuck in attack animation till your following turn.
Strikershad#73057 shared this idea