He persuaded Muqtada al-Sadr's rebel fighters to leave the shrine under an agreement that will also see U.S.-led foreign forces pull out of the city.
But the thousands of people at the shrine were themselves playing a vital role in the deal. That's because al-Sadr's Imam Al-Mahdi Army fighters were able to blend in with the throng as they left the shrine.
Hamid al-Khaffaf, an aide to al-Sistani, said yesterday that opening the shrine is an "integral part" of the agreement. "The office of Grand Ayatollah al-Sistani asks the Iraqi government to allow the visiting civilians to be given permission to enter the sacred shrine [of Imam Ali] on the condition that they leave the shrine by Friday morning at 10 a.m., at the very latest," he said. "This condition of allowing civilians to enter the shrine is an integral part of the agreement we have reached [between al-Sistani and al-Sadr] and you will hear, in the coming hours, positive initiatives for Iraq and the city of Al-Najaf and a solution for the salvation of the sacred shrine."
Under al-Sistani's peace plan, all armed groups must leave Al-Najaf and nearby Al-Kufah, where a mortar attack and gunfire yesterday left 74 people dead and more than 350 wounded.
Security will be handed over to Iraqi police and all multinational forces must leave. And the government will compensate victims of the fighting.
Yesterday, Iraq's secretary of state for military affairs, Qasim Dawud, said he hopes peace will also spread to other Iraqi cities. Dawud said al-Sadr will not face arrest and that his movement will be treated as a political group as soon as it lays down its weapons.
"The Al-Mahdi Army, as long as they are going to put down their arms -- so definitely we are going to deal with them as a political current or as a political group, and every political group in Iraqi society has the right to participate in the political process," Dawud said.
But while some of al-Sadr's militia tossed their weapons into wooden carts today, others were still armed and defiant. Reports say many took their weapons home -- ready, one fighter said, to take them back "if the situation deteriorates."
Another spoke of victory. "We are victorious. It's obvious, and the people coming to Al-Najaf know it," he said. "We will do as we are told by the leader [Muqtada al-Sadr], and we wish the best for Iraq."
(compiled from agency reports)
Factbox: Iraq's Holy City of Al-Najaf
For the latest news on Iraq, see RFE/RL's webpage on "The New Iraq".