Iran believe that Iraq forward Alaa Abdul Zahra was not eligible to play in the fixture, which Iran lost on penalties, as he reportedly failed a doping test while playing for his club Tractor Sazi of Iran in September.
However, following a hearing the AFC decided that no action is required and that the result should stand.
"The AFC Disciplinary Committee met on 25 January 2015 following a protest lodged by I.R. Iran Football Federation on 23 January 2015 regarding the eligibility of Iraqi player, Alaa Abdul Zahrah Khashen Al-Azzawi, to participate in the quarterfinal match between I.R. Iran and Iraq on 23 January 2015," the AFC said in a statement.
"The AFC Disciplinary Committee from 2:30pm heard oral evidence from two officials of the I.R. Iran Football Federation, deliberated the matter based on its merits, and decided that the protest was unfounded. The protest was therefore dismissed.
"Due to the urgency of the matter, the terms of the decision were initially notified to the I.R. Iran Football Federation at 6:20pm. The full grounds of the decision will be communicated tonight in due course. The I. R. Iran Football Federation will have the right to file an appeal in accordance with the AFC Disciplinary Code."
Iraq will play South Korea in an Asian Cup semi-final on Monday.