What “victory”? There was no battle, no seige. The Savannah Mayor, Aldermen, and Ladies of the City crawled to General Geary on their knees and begged him not to destroy the city or harm the citizens and they would not resist.
On the contrary, none of the Northern troops wanted to burn, rape, or pillage Savannah. None of the Command (bad guys) wanted to either. After the fall of Fort McAllister in Richmond Hill (earthen Fort that was only conquered because of low tide) and the other brick fortress Forts falling before, Savannah was deserted when the good guys fled across the river to SC.
Savannah having a large population of Jews, a grand Masonic Lodge, lack of opposition, the troops had a change of heart compared to the blood lust in the north and central part of the state.