With Lucian Goian marshalling the team expertly, they have conceded just twice at home in four games so far and so much credit for that goes to a clever choice of ground and playing style implemented by Alexandre Guimaraes.
The pitch at the Mumbai Football Arena (MFA) is very small and it suits the compact way in which the Mumbai defence is organised. Despite not having the cream of Indian full-backs at their disposal, Mumbai City's small pitch has ensured they won't get exposed much with Gerson and Goian able to help the full-backs get out of tight situations.
On Friday night, their attack clicked as well, racking up four goals, but much of that had to do with Delhi's wayward defending - which has been a big factor in them enduring a six-game losing streak.
All four goals from Mumbai City had basic mistakes from Delhi behind them. After Arnab Das Sharma's reckless challenge on Everton Santos, Achille Emana went on to smack the post with his penalty. However, none of the Delhi defenders followed up and allowed Lucian Goian to convert the rebound.
Less said about Mumbai City's next two goals, the better it is for Delhi Dynamos. For all the emphasis on possession and passing style, the Lions' defensive organisation has been woeful. So it proved when Everton Santos outjumped Pritam Kotal and Matias Mirabaje at the near post to score a header from Emana's freekick, with both of them not taking the initiative to put the Brazilian under pressure.
It was the same story again in the second half when Everton Santos once again popped up at the near post to send a looping header in. Clearly, the Delhi defence had not learnt their lessons. For Balwant's goal, the entire defence went to sleep with Emana picking out Balwant in between the central defenders with ease. It didn't help that Pratik Chowdhury stepped up to catch Balwant offside but his partner failed to read that move and played the Punjabi striker onside.
But it was not always plain sailing for Mumbai City on the night. Delhi did create chances in attack but the lack of a proper finisher let them down. Miguel Angel Portugal deployed Guyon Fernandez as the target man in the absence of the injured Kalu Uche and the Curacaoan showed why he is not a clinical finisher. There was this one notable chance for him when Romeo stood up a delivery from the byline for him. With the goalkeeper and the defenders stranded, all he needed to do was to nod the ball in from 5 yards out but he glanced it pitifully wide.
Miguel Angel Portugal does not even have an Indian striker as cover and had no choice but to play Guyon as his striker, which puts serious questions on their recruitment strategy. On the other hand, in stark contrast, Balwant Singh justified Mumbai City's belief in him with his fifth goal of the season - the highest scoring Indian this time around.
Mumbai City now have a very good platform from which to plan their assault on one of the playoff spots while Delhi have fallen into a rut. And in a punishing league like ISL, one feels the time is running out for the capital-based side.