It IS a victory for the Mahdi army.
Once again, instead of being wiped off the map they were allowed to get out and will regroup.
They are fighting a stalling strategy, and it is working. I don’t diminish the victory in this individual battle, but Sadr is not losing as long as he can keep going back to Iran for fresh arms and troops.
CNN, Monday 3/31
***The mood Monday on the streets in Basra was quiet, said al-Askari, the prime minister's spokesman. Shops opened in the morning, and the movement of people was almost back to normal in the center of town.
Troops and police, whom the U.S. and Britain have backed, are in control of much of Basra, and local security forces are going house-to-house in some districts to confiscate weapons and chase the outlaws and the criminal and smuggling gangs, the spokesman said.***
Sadr lost Basra so he's declared the loser at least for this round.