Yes, that is posible. The loosing house still has to retreat and if the area contains a Power token or garrison token that token is romoved. If that area contains a port with ships, these ships will be destroyed since ships can't exist in an port connected to an area that isn't controlled by the ship owner.
The Sword Icon: During the “Combat Resolution” step, the player who won the combat (i.e., the victor) counts the number of Sword icons on his House card. For each Sword icon, an enemy unit in the embattled area must be destroyed (see “Casualties” on page 20).
We had a battle once that House Tyrell attack House Lannister. Both have only one Footman and no support received. Tywin brought his Valyrian Steel's Blade to beat Mace's Footman alone after Lannister's Footman was removed by Mace's text ability. House Tyrell retreat and the embattled area is empty after the combat.
If Mace is defending one Footman's attack and lose the combat, the condition will fit your question.