Mumbai Indians, which licked dust in all their previous matches, bounced back into reckonings as both Uthappa and Bravo thrashed the home side bowlers into smithereens, while Riders tasted its second successive defeat after two consecutive victories. The duo added 113 runs in 90 balls for the fourth wicket.
Chasing 138 to win, The Mumbai side began on a shaky note as they lost three wickets with the score reading 25. Then Bravo came in and smashed the Riders bowlers all over the field scoring 64 invaluable runs in 53 balls studded with one towering six and for rollicking hits to the fence, while Uthappa chipped in 37 runs in 37 balls with five fours much to the disappointment of a packed Eden house.
The fourth wicket partnership of Bravo and Uthappa broke the earlier 111-run partnership tournament record of Deccan Chargers' Rohit Sharma and Andrew Symonds.
But the most turning point of the match was the vital catch miss by local lad Debrabrata Das when he muffed an easy chance by Uthappa when the Mumbai Indians' score stood at 38 for three.
Dashing Sri Lankan Sanath Jayasuriya spun magic returning with a fabulous figure of three for 14 and then scoring 18 to bag the Man of the Match award.
Stand-in Mumbai captain Shaun Pollock gave the initial breakthrough chipping in two prize scalps of Sourav Ganguly and Brendon McCullum to restrict Kolkata Knight Riders to 137 for eight.
But the home side got a semblance of respectability through Laxmi Ratan Shukla (40) and Debabrata Saha (29), which gave the Kolkata side some glimpses of hope from a hopeless situation earlier in the match.
Jayasuriya had David Hussey and Ajit Agarkar caught by Ashish Nehra at long-on in identical fashion. Between those two dismissals, he also removed Mohammad Hafeez while Ponting was run out as Kolkata slipped from 74-3 in the 12th over to 77-6 in the 14th and then to 90-7 by the 16th over.
Shukla then produced a blitzkrieg in which he dispatched the ball to all parts of the ground, much to the excitement of a packed house.
Earlier, Pollock, leading the team since Harbhajan Singh's ouster from the tournament because of a ban, produced an inspired opening over in which he dismissed openers Brendon McCullum and Sourav Ganguly.
Pollock had Ganguly caught by Sanath Jayasuriya at wide slip immediately after the left-hander had dispatched a delivery from the South African to the mid-wicket boundary with a short-arm pull.
Pollock then trapped McCullum leg-before as he shuffled across.
Debabrata Das was the third batsman to be dismissed, his flurry of shots on the leg side getting him 29 off 19, but a slash outside off giving Dwayne Bravo a wicket in his first over. Robin Uthappa, fielding at point, accepted the catch gleefully.
Mumbai Indians went without their captain Sachin Tendulkar and banned Harbhajan Singh.
Pollock gave all the credit of their victory to Jaysuriya and the brilliant partnership of Bravo and Uthappa, while Sourav said they should posted a chalenging total to the Mumbai side.