Enwer Annayev came off the bench to score the decisive goal in the 83rd minute, giving Ahal FK a 1-0 win
The 19-year-old forward finished a precise through ball from Basim Gurbanberdiyew with a calm left-footed strike
Both substitutes, Annayev and Gurbanberdiyew, combined almost immediately after entering in the 79th minute
Substitute Enwer Annayev struck late as Turkmenistan's Ahal FK stunned Mohun Bagan Super Giant 1-0 in their opening Group C match of the AFC Champions League 2 at the Salt Lake Stadium on Tuesday.
The all-important strike came in the 83rd minute when the 19-year-old forward, who had come on just minutes earlier, latched onto a precise through ball from Basim Gurbanberdiyew and slotted home his left-footed shot to the bottom right corner.
The two substitutes had combined almost instantly after being introduced in the 79th minute, with Gurbanberdiyew replacing Alibek Abdyrahmanow and Annayev coming in for Magtymberdi Berenow.
Gurbanberdiyew showed fine vision to thread the pass inside the box, while Annayev kept his composure to finish across the face of goal and secure a precious away win.
Earlier in the 32nd minute, Mohun Bagan had a close shave when Elman Tagayew's deflection off a low cross wrong-footed goalkeeper Vishal Kaith, only for the ball to come off the crossbar.
The ISL champions' best chance came in the 69th minute when Dimitri Petratos and Jason Cummings combined inside the box to set up Jamie Maclaren, but Ahal's young goalkeeper Kakageldi Berdiyev produced a brilliant save to deny the Australian striker from point-blank range.
Despite late urgency, Mohun Bagan struggled in attack, sorely missing the injured Manvir Singh.
Their wing play remained ineffective, while the defence looked rusty and error-prone, inviting pressure throughout the contest.
The defeat leaves Mohun Bagan with some tough questions ahead of their next Group C outing, an away clash against Iranian giants Sepahan on October 21.
