Mumbai City FC began its AFC Champions League (ACL) campaign on a disappointing note as it suffered 0-2 defeat at the hands of debutants Nassaji Mazandaran of Iran here on Monday.
Ehsan Hosseini (34th minute) and Mohammadreza Azadi (62nd) scored for the visiting side.
Mumbai made a bright start and almost opened the scoring in the ninth minute when Jorge Pereyra Diaz slipped the ball through to Lallianzuala Chhangte, who shot from a tight angle missed the target.
With 11 minutes remaining in the half, Nassanji took the lead. Hossein Zamehran picked up possession 20 yards from goal, the playmaker turning swiftly to play Ehsan Hosseini in with a defence-splitting pass, and he slotted calmly into the bottom corner of the net to put the Iranians in front.
Bipin could have ensured Mumbai went into the break level a minute into first half injury time only to shoot off target after being found in space as Chhangte rolled the ball across the face of the goal.
The Iranian outfit rounded the tally when substitute Farshid Esmaeili robbed Akash Mishra deep inside his penalty area and had the presence of mind to roll the ball into the six yard box, where Azadi was left with the simplest of finishes.
Vikram Partap shot across the face of goal and Chhangte glanced his header wide as Mumbai sought a late lifeline but Nassaji saw out nine minutes of additional time to taste victory in its maiden AFC Champions League appearance.