Chasing a mammoth 196 for victory, Kolkata Knight Riders's hopes depended largely on getting off to a quickfire start, but their top order came undone against a spirited performance by the Mumbai Indians pacers with the new ball.
KKR openers Sunil Narine and Shubman Gill could never got going in the Powerplay, which saw them attempt rash shots to give their wickets away.
Trent Boult made the perfect start for Mumbai as he started with a maiden over to Gill.
At the other end, James Pattinson made the mistake of bowling too full and on the pads to Narine, which he carted for a six.
Boult then rocked KKR early when he got Gill caught at midwicket as he pulled it straight to Kieron Pollard, in the third over.
Jasprit Bumrah, brought into the attack, for the fourth over ramped up the pressure even further by conceding just a single in his opening over.
Pattinson dented KKR's hopes further with Narine's wicket, done in by the short ball, as he got the edge trying to play the pull shot to perish for 9.
KKR could not make most of the field restrictions in the Powerplay as they limped to a lowly 33 for two in the first six overs.
Even though Captain Dinesh Karthik and Nitish Rana looked to make a comeback in the middle overs, the slow start meant that KKR had a lot of catching up to do against a top quality Mumbai Indians bowling attack.
By the time, dangerman Andre Russell walked out to bat in the 12th over, the match was beyond reach with the asking rate touching as far as 15.
KKR finished on a disappointing 146 for nine in their 20 overs, to lose by a big margin of 49 runs.