Mohun Bagan scored through Chidi in (17th, 33rd, 46th and 66th minutes) and newcomer Manish Mathani (22nd).
For East Bengal, Yusif Yakubu scored a brace (35th and 44th) while Nirmal Chhetri scored in the eighth minute.
With four goals to his credit, Chidi was adjudged the man of the match. Bagan’s defence was nowhere to be seen when Rennedy Singh blasted in a corner from the right that went straight to Nirmal.
With no one to block him, Nirmal scored a free header right in front of the goal as East Bengal took the lead in the eighth minute.
East Bengal scored another when Yusif Yakubu scored from a beautiful back flick by Abel Hammond but the referee ruled out the goal, declaring it an off-side minutes later.
In the 17th minute, a surging Chidi scored his first which was set up by Surkumar Singh from the right. The Indian medio tackled N Govin Singh and Mehrajuddin Wadoo before crossing it to Chidi who was bang on target. Mohun Bagan went ahead five minutes later with a goal by Manish Mathani in what appeared a goalkeeping lapse by East Bengal’s Abhra.
Meanwhile, Salgaocar SC defeated Sporting Clube De Goa 3-2 in their encounter at Margao. Nathaniel Amos (10th) score the first goal for Sporting but Deevan D’Mello levelled the score within two minutes. Salgaocar made it 3-1 through two goals from Eneke Ikenwa (22nd, 30th). Joseph Pereira (50th) pulled one back for Sporting.