In the last four overs of their innings, Mumbai Indians could add only 33 runs and lost six wickets, finishing the innings around 20 runs short of what they looked good for. Defending a below-par target on a true pitch, in a ground with short boundaries, against tough opponents, in a knockout match and without Lasith Malinga, Mumbai needed their bowlers to step up, along with their 12th man - their band of aggressive supporters in the stands. But around 10 pm, the crowd lost its voice and the bowlers their sting.

Both of Mumbai's grounds are in the posh neighbourhood along the Marine Drive, replete with art-deco buildings and home to the who's who of Mumbai. Rules like the 10 pm ban on loudspeakers are best implemented in such parts. The rule gets countered to an extent when Mumbai bat second as every four or a six reverberates in the stands, making the home support real. Not when they bat first.

On Wednesday night, the sudden dip in energy levels was infectious as Mumbai's fielders were clumsy early in the second innings - Rohit Sharma dived over one at extra cover to let the ball run to the boundary before Ambati Rayudu and Harbhajan Singh let a skier drop between them. That a very confident and extended lbw appeal - which seemed pretty much out on the replay - from Praveen Kumar and the surrounding fielders didn't go in Mumbai's favour further sapped the spirits. By the end of six overs, around 10.20 pm, Chennai Super Kings were already running away with the match at 60 for 0.

The first half had been anything but dull. Outside the ground, the street extending from Churchgate station to the Marine Drive was packed on both sides with people waiting to get inside the ground, the regular rush of commuters and hoards of hawkers trying to offload their IPL T-shirt stocks.

The din continued inside the ground too. Mumbai batted, and after a slow build-up, Lendl Simmons and Michael Hussey got the innings going. The smoke generators hissed, the music blared, the cheerleaders did their routines, the stands - apart from a few specks of yellow - turned completely blue. Once in a while a bit of yellow mushroomed at the fall of wicket only to be consumed by blue as the home team's batting giants strolled out one after the other. A young fan, sporting the blue and gold jersey, tirelessly pumped his air-piston horn. At about 9.45 pm, when the first innings ended in an anti-climactic implosion for the home fans, he broke the piston mechanism.

Unlike their batting, which had underperformed before making a resounding comeback towards the latter half of the tournament, Mumbai's bowling had lacked potency even when Lasith Malinga had been around. In their previous match, the bowlers had almost shut the door on their team by giving away 189 to Rajasthan Royals, but that was all overshadowed by an explosive response from their batsmen. The noise at the Wankhede Stadium that night had perhaps played its part in sowing the seeds of doubt in the opposition. On Wednesday night, it was the bowlers' turn to mutually feed off that energy, but apart from Harbhajan and Praveen, no one posed consistent questions.

Harbhajan bowled slower through the air and extracted some bounce from the Brabourne pitch that had also benefitted R Ashwin and Ravindra Jadeja in the first innings. The double-strike in his first over - both Dwayne Smith and Faf du Plessis fell lofting the ball to the fielders in the deep - was the injection his team, and the crowd, needed to wake up from their slumber. Apart from Sachin Tendulkar in the past and Lasith Malinga, the Mumbai crowd only really seems to connect with Harbhajan and Kieron Pollard. So Harbhajan striking early created a buzz. He bowled his four overs one after the other and gave away 27 runs. During his spell, the three overs from the other end only went for 22, slowing Super Kings down.

Pragyan Ojha had played his part early on by picking up the wicket of Brendon McCullum with a cleverly flighted delivery. His first two overs cost 14 runs and it looked like he was set to play an important role after Harbhajan was done with his quota. Instead, it was Ojha's third over - the 16th - that ended the contest as he was carted away for three sixes, the over costing Mumbai 20 runs. Suresh Raina and David Hussey, who did the damage, trotted out at the remaining runs with ease.

As the 'C-S-K, C-S-K' chants grew louder, the counterbalancing 'Ma-lin-ga, Ma-lin-ga' would have been missed. So would have been Malinga's ability to create opportunities and fire hope. With not much inspiration on the field from the home side, the young boy with the horn spent almost the entire innings trying to fix the mechanism. In the 18th over, an over before the finish, he walked out with the broken horn.

Devashish Fuloria is a sub-editor at ESPNcricinfo