Iran beat Iraq in Olympic qualifier
The two teams will meet again on June 23 in Tehran.
Musliman's goal came on a counter attack in the 30th minute before a crowd estimated at 18,000 at the half-empty Franso Hariri Stadium in Arbil, the capital of Iraq's semi-autonomous northern Kurdish region.
"To lose is not the end of the universe. This is football. Our team played well but the preparation of the Iranian team was better than ours," Iraqi coach Nadhim Shakir told a news conference after the match.
"We gained a good result from the Iraqi team - its play was good but cooperation between the players was weak," Iranian captain Sayed Ridha said.
The neighbouring countries have both qualified for the Olympics four times.
Iraq played in 1980, 1984, 1988 and 2004, when it reached the semi-finals. Iran qualified in 1964, 1972, 1976 and 1980.