The Goan side were made to toil hard by the Mumbai-based side but a late goal ensured that the three points were sealed by the home team...
The win takes the defending champions to the second spot while Air India continue to languish in the bottom half with a paltry three points from six matches.
Dempo goalkeeper Subashish Roychowdhury was rested with Tyson Caiado earning his first I-League start this season, while Godwin Franco replaced Climax Lawrence who is suspended with to a two-match ban.
Air India interim coach Anthony Fernandes started with Ezeh Henry and Junior Obagbemiro in the attack.
The first half failed to create any flair as both sides held a defensive resolve. There were a couple of strikes flying all over the place but none to trouble the goalkeepers.
Pradeep Mohanraj of Air India had an opportunity to put his side in the lead but his shot missed the target while Ryuji Sueoka saw his header from inside the box go wide in the opening ten minutes.
In the 12th minute, Tyson Caiado saved an initial attempt by Junior and on the rebound, Henry followed it up. However his touch was too heavy which saw the ball go out of play.
Nine minutes later, Clifford Miranda was well on his way on the right, but the Dempo captain let go of a rather weak shot which did not trouble Air India goalkeeper Sukhwinder Singh.
The closest anyone came to scoring was in the 38th minute when Air India skipper Micky Fernandes' free-kick hit the top of the crossbar and fell back in play before the Dempo keeper held the ball.
Just as play resumed, in the second half, Ryuji Sueoka tried to tap in Clifford Miranda's cross in front of the Air India goalmouth that was kept out by Sukhwinder Singh. On the follow-up, Abranches saw his shot come off the far post before the ball was held safely by the Air India custodian.
Abranches went on to miss another opportunity in the following minute as he headed wide a Samir Naik cross from inside the box. Air India had a chance of their own as Junior saw his header go straight into the hands of Caiado from a Souvik Chakraborty cross.
Micky Fernandes, on a solo run from inside his own half, tested the opposition custodian from 30 yards out which saw Caiado collect the ball on second attempt in the 71st minute.
Substitute Rohan Ricketts did well to set up Romeo Fernandes on the right, while the latter's shot was blocked out by Air India goalkeeper Sukhwinder Singh. Romeo Fernandes was in the thick of things after coming on as his cross saw Peter Carvalho head wide, much to the disappointment of the Dempo bench late in the game.
However Dempo didn't lose hope just as yet as Joaquim Abranches scored the winner in the 90th minute. Ryuji Sueoka crossed from the right which found Romeo on the far post. The youngster squared the ball across the goal for Abranches to tap in and seal the victory.
It was certainly a hard fought victory for Dempo SC as it is certainly a warning sign for them to fill up the empty foreign player spot. Air India would be disappointed but a lack of concentration typifying a team fighting for relegation late in the game will not go unpunished against a side like Dempo.
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