Goalkeeper Vishal Kaith's indiscretion and poor defensive organization during the counter-attack cost ATK Mohun Bagan dearly as Chennaiyin FC rallied from a goal down to beat hosts 2-1 in the opening Indian Super League encounter between the two teams, here on Monday.
It was Ghanaian forward Kwame Karikari, who came in as a substitute in the second half and turned the match on its head, by first equalising in the 64th minute and then setting up India international Rahim Ali for the winner in the 83rd minute.
This was after Manvir Singh's powerful left-footer in the 27th minute gave the Mariners 1-0 lead.
Another defeat with a poor second half show will now increase the pressure on Mohun Bagan's coach Juan Ferrando, who is likely to get the boot anytime during the season as the team's performance under him has been simply put - below par.
However Bagan started the match in a positive fashion as Manvir, who has fallen out of favour with national coach Igor Stimac, played a one-two with Dimitri Petratos before slotting it past Chennaiyin goalie Debjit Majumdar.
But in the second half, once Kwame was introduced, things changed rapidly for Chennnaiyin as there was more thrust in the attack.
One such move in the 63rd minute saw Kwame within a striking distance of goal but goalie Kaith's rough challenge got Chennaiyin a deserving spot kick which the Ghanaian himself converted.
While Bagan did keep attacking, there was distinct lack of penetration in the attacking third but against the run-of-play, Chennaiyin hit on the counter.
Kwame got a loose ball down the wide and sprinted down before he kept a cut back for Rahim, whose deft right-footed placement found the left-corner of the net to give his team the decisive lead.
Bagan had a chance during dying moments when substitute Liston Colaco's curling free-kick from the edge of the 18-yard box was brilliantly saved by a diving Debjit.