In the first election since the Islamic State of Iraq and the Levant (ISIL) militant group was defeated in the country, Iran-backed Shiite militia chief Hadi al-Amiri's bloc was in second place, while Prime Minister Haider al-Abadi, once seen as the front-runner, trailed in third.
Alliance of Shiite cleric Muqtada al-Sadr is set to win Iraq's parliamentary elections - an unexpected outcome that has caught the attention of Iranian media.
Preliminary results showed that Iranian-backed al-Ameri's bloc was in second place, while al-Abadi's Victory Alliance was third. The Associated Press says he has "in recent years sought to recast himself as a populist, railing against corruption and failing services". The country is also waiting to hear results from Kirkuk, an oil-rich city disputed by Baghdad and Iraq's northern, autonomous Kurdish administration.
Abadi offered a statement of congratulations to Sadr for his victory, and for encouraging a secure atmosphere during the vote. Corruption has been at the top of Sadr's agenda for several years.
Mr Al Sadr made a concerted effort to appeal to marginalised and disillusioned Iraqis while styling himself as a reformist leader determined to effect comprehensive change to a failing political class. Asked about the U.S. government's possible softened position toward Sadr and his alleged proximity to Riyadh, Hassan Danaiefar told Entekhab news site on May 15, "Some of this talk is speculation".
While speculation swirls, the next concrete step remains completing the vote count and firming up the final makeup of Iraq's new 329-seat parliament.
Any attempt to form a government that would threaten the influence Iran has built up in the 15 years since the fall of Saddam Hussein looks certain to face opposition from Tehran.
According to Iraq's official election commission, some 10.8 million Iraqis - out of 24 million eligible voters - took part in the vote, representing a turnout of 44.5 percent. More than 2 million people are displaced by war, majority Sunnis.
Reuters could not independently verify the document's authenticity but the results in it for the 16 announced provinces were in line with those announced by the commission.
O'Neill said al-Sadr cleverly renamed his "Mahdi Army" the "Peace Brigade" and said the name can be easily used as a propaganda tool to hurt people like Trump who oppose it. The other winning blocks, though, will have to approve his nomination.