Army XI rode on a second half strike to upset Mohun Bagan 1-0 in the Calcutta premier division-A game here on Tuesday.
P. Jain scored the all-important goal in the 48th minute of the match on Mohun Bagan ground.
Receiving a midfield pass from Shadip Rai, he finished with a spectacular left footer.
Army XI are now in the second position of the league with 12 points from seven games. Mohun Bagan are three rungs lower in the league ladder gleaning eight points.