Bartholomew Ogbeche scored the all-important goal to steer Mumbai five points clear with 25 points while the Kolkata club are second with 20.
One can expect a close encounter with the Islanders keen to strengthen their position at the top while the Kolkata club will be eager to overtake their opponents and secure top spot.
In their nine games so far, Bagan have managed to score just one goal in the first half, and against Gerard Nus' team, they struggled in the first 45 minutes but utterly dominated the second.
Chennaiyin put up a dominant display against Bagan and if it wasn't for some stunning saves from their goalkeeper Arindam Bhattacharya, the southern side could have walked away with all three points.
For the sheer amount of chances that Chennaiyin create in games, they have managed to score just seven goals so far in the league.
David Williams’ first-half strike proved to be the difference between the sides as the Kolkata club secured their fifth win in seven matches to remain in second place.
A win for either team will be a massive statement in the league, which is currently topped by Mumbai City FC.
Though aware of the challenge that awaits for his side, ATKMB coach Antonio Habas has his sights set on nothing less than three points.
As for Mohun Bagan, a win means that they will be tied on points with Mumbai City FC, who are the leaders with 13 points.
The Goa players are gradually coming to terms with what their new coach Juan Ferrando wants from them, as has been witnessed by their attacking brand of football, which has produced seven goals.
Despite all these, Hyderabad gave a good account of themselves, coming back from one goal deficit to secure a 1-1 draw, maintaining their unbeaten streak.
ATKMB, who lost their last game to Jamshedpur, might have emerged victorious in their other three games, but there is a point of concern.
ATKMB remain second in the table with nine points from four games while Jamshedpur FC climbed two spots to seventh.
Jamshedpur, on the other hand, haven't been enjoying a great start with two draws and a loss in their three matches.