The blast occurred around 7:00 p.m. (1600 GMT) on Friday when a suicide bomber blew up himself in the village of al-Asriya while the winners were being handed the trophy, local police and medics said.
The Islamic State terrorist group claimed responsibility for the attack that wreaked carnage on the field where supporters, officials and security forces were gathered after the game.
The village is near Iskandariyah, a town about 40 kilometers south of Baghdad.
A medic at Iskandariyah hospital confirmed the toll and warned it could rise further.
The US State Department condemned the suicide bombing and sent condolences to the bereaved.
“The United States remains committed in its support to the Iraqi people and the unity of Iraq,” State Department spokeswoman Elizabeth Trudeau said in a statement.
The United Nations Assistance Mission for Iraq says a total of 670 Iraqis were killed and 1,290 others injured in acts of terrorism, violence and armed conflict in February.