Although Mohun Bagan's Sourav Das (47') opened the scoring, they could not maintain their lead as keeper Asanja Daimary's howler in front of goal (84') let in Dip Saha's long ranger. The Kolkata giants could not be separated even after extra-time and East Bengal held their nerve in the shoot-out to lift the trophy.
Jo Paul Ancheri made two changes to the starting line-up that started in Bagan's 2-1 victory over SAIL Burnpur. Pulak Baruah and Debanna Chakraborty were relegated to the bench as Deep Saha and Lalthan Khuma slotted into the midfield.
Mohun Bagan started the match on the ascendency, creating a flurry of chances from the left flank through Subha Ghosh. Ghosh made a darting run through the left flank after skipping past two challenges but a timely tackle from East Bengal's M Clinton averted the danger on that occasion.
Bagan could have taken the lead in the 21st minute but Didwm Hazowary's dangerous curling ball was only half-heartedly headed by Asif Ali Molla.
East Bengal gradually started to see more of the ball but lack of creativity in the attacking third was not helping their cause. They had the chance to draw first blood when Bagan keeper Asanja Daimary failed to make a clean save but there was no Red and Gold shirt to pounce on the rebound.
Ghosh remained the livewire for Bagan. He delivered an inch-perfect cross from the left but Sourav Das could not rise high enough for a header and opposition keeper Ayan Roy came out of his line to make a comfortable save.
Mohun Bagan's Sourav Das finally broke the deadlock from Ratan Das' deep throw into the box. The ball dropped clumsily in the six-yard area and as East Bengal's defence failed to clear the ball, Das found the net from close range.
After conceding, East Bengal re-started with a sense of urgency and started piling pressure on Bagan's backline. Centre back Asif Ali Molla fouled Lalcchanhima in a dangerous area and Suranjit Singh's effort from around 25-yards could have levelled things up had it not flown inches wide from the post.
East Bengal finally notched an equalizer after Mohun Bagan goalkeeper Asanja Daimary failed to control Dip Saha's long-range effort. The goalkeeping howler took the game into extra-time.
Bagan continued with their route-one tactic which failed to trouble East Bengal's backline. East Bengal looked composed as they kept knocking the ball around in midfield.
Both sides failed to find a winner after 120 minutes of play in the sweltering heat of Barasat and the match proceeded to a penalty shoot-out.
Bagan missed the first two attempts whereas East Bengal made their chances count. It was Saha who converted the winning tie-breaker, tilting the result towards East Bengal.
East Bengal thus registered their 29th IFA Shield title, the most by any team in the history of the tournament.