Down 0-1 at the breather, Mahindra leveled in the 46th minute as K. Aseem dribbled past Bagan's Sur Kumar Singh and fed an unguarded Svetozar who headed in.
Mahindra, desperately needing a win to move into the last four, were all over their opponents in the second session, but could not break the 1-1 deadlock.
Such was Mahindra's pressure that the Bagan supporters lost their cool and vented their ire by pelting stones and water bottles towards the Mumbai team's goal. Custodian Subhasish was hit by a missile and had a cut on his forehead. The match had to be stopped for eight minutes.