The scoreline could have been embarrassing for Indian Arrows but Bagan's profligacy in front of goal forced them to be content with a win by two goals.
The Indian Arrows chose to stick to the starting lineup that secured a 1-0 win over Shillong Lajong in their previous match.
Sankar Lal Chakraborty made two changes to the side that drew 2-2 against Aizawl. Shilton Paul got his first start in this edition of I-League along with Yuta Kinowaki in place of Sankar Roy and Britto PM respectively.
Mohun Bagan started dominating proceedings right from the first whistle and they could have taken the lead as early as the second minute. Arijit Bagui floated in a cross from the right flank and Boris Singh's defensive header fell to an unmarked Henry Kisekka. The Ugandan pulled the trigger at the first instance but failed to keep his shot on target.
Arrows sat deep in their defensive half and were not allowing space for Bagan attackers to roam around. Chakraborty stuck to his predictable strategy of using the flanks to attack which was well contained by the likes of Boris and Asish.
On the 24th minute mark, Bagan wasted another chance to go in front when Kisekka had the entire goal at his mercy but chose to shoot straight at a defender on the goal line.
Dipanda scored with his head on the half-hour mark after Kisekka wrestled past two defenders to set him up within sniffing distance of goal.
They got their insurance goal right before the halftime break when Boris handed the ball inside the penalty box. Dipanda stepped up to take the spot-kick and rolled the ball beyond the reach of Prabsukhan Gill towards the keeper's left.
Although Bagan continued to enjoy the bulk of the possession after the resumption of play, they looked to slow things down in the attacking third. In the 67th minute, the visitors could have found their third if Dipanda had beaten Gill with his header from inside the six-yard box after Bagui dished out an inch-perfect cross.