Iraq's national football team had earlier beaten South Korea 4 - 3 after penalties, to book their place into the Asia Cup 2007 final against Saudi Arabia.
Football-mad Iraqis have had little cause to celebrate during four years of unrelenting violence and chaos, but have been following their team's progress in the Asia Cup at home and in cafes.
Many Iraqis bought extra fuel to make sure generators kept going during Wednesday's match, since the national power grid has been unreliable in keeping domestic appliances running.
During a rare moment of national unity, the bombings were a sharp reminder of the ongoing sectarian violence that has killed tens of thousands of people.
In Sadr City, a sprawling Shia area of Baghdad, women had earlier thrown sweets to fans with Iraqi flags draped over their shoulders.
Ice cream and juice shops gave away free treats - a rare sight in the district, which is a stronghold of the Mehdi army of Moqtada al-Sadr, a prominent Shia leader.
Thousands of fans poured into the streets in all areas of Baghdad, Basra and Kerbala in the south, and Kurdish cities such as Arbil, Kirkuk and Sulaimaniya in the north.
State television flashed a warning from military commanders urging people not to fire guns into the air, but the warning appeared to go unnoticed as jubilant fans fired pistols and AK-47 assault rifles.
The crackle of gunfire could still be heard in Baghdad hours after the match ended.
One person was killed and 17 wounded in the capital by falling bullets, police said.
Three people were killed and about 50 injured by falling bullets on Saturday after Iraq beat Vietnam to reach the semi-finals.