Dempo SC scored through their foreign players, Koko Sakibo and Ryuji Sueko. While Sakibo gave the defending champions the lead with a powerful header from close range in the 21st minute, Sueko converted a penalty in the injury time to ensure Dempo SC return home with three full points.
Nurudeen Salau had restored parity for United Sikkim in the 57th minute. In fact, once it looked as if the I-League debutants would snatch a valuable point from Dempo but they went down fighting after a penalty was awarded against them in the 93rd minute.
With seconds left in the game, Climax Lawrence fell down in the penalty box after an innocuous push by a United Sikkim defender.
Referee Pratap Singh awarded a penalty and while United Sikkim players protested the decision, central defender Sandesh Jhingan appeared to have slapped Dempo player Peter Carvalo who slumped into the ground.
Jhingan was shown a direct red card and Sueko had no problems in converting the resultant penalty.
Pratap Singh had earlier disallowed a goal scored by United Sikkim captain Anwar Ali in the 10th minute.
Dempo coach Armando Colaco admitted that United Sikkim was a better side today.
"United Sikkim played better in their home ground and with full crowd support. Luckily we got three points and it is the experience of the Dempo players that led to the victory," he said.
United Sikkim were more incisive in their attack and created several goal-scoring opportunities in the first half, keeping rival goalkeeper Subhashish Roy Chowdhury on his toes.
Buddiram Tudu missed two open chances, while Linekar Machado sailed past three Dempo defenders from half-line but could only manage a weak shot from close range, which was easily saved by Man-of-the-Match Chowdhury.
