Tripathi defined the run-chase with an unbeaten 74 off 42 balls while Iyer - playing in only his second IPL game - made 53 off 30 balls as Kolkata raced to 3-159 in just 15.1 overs on Thursday.

Defending champions Mumbai had earlier wasted a brilliant start of 78 provided by Quniton de Kock (55) and captain Rohit Sharma (33) to reach only 6-155 after Kolkata skipper Eoin Morgan had won the toss and opted to field.

"It's been a long time since we've played like this," Morgan said. "To hold such a strong Mumbai team, and chase it down in the manner we did gives us confidence."

Iyer dominated the world's top-ranked pace attack of Jasprit Bumrah (3-43) and Trent Boult, who was removed from the attack after conceding 23 off his first two overs, as Kolkata took 40 off just the first three overs in the run-chase.

Bumrah claimed two late wickets when he had Iyer clean bowled in his return spell off a slower delivery but, by then, the left-hander had done the damage, hitting four boundaries and three sixes.

Morgan holed out in the deep off Bumrah's short pitched delivery, but Tripathi ensured the emphatic win by dominating the bowlers while hitting eight boundaries and three sixes.

Earlier, Kolkata had made good a recovery after Rohit and de Kock had provided a solid start off 55 balls.

Rohit holed out at long-on midway into the innings and fast bowler Prasidh Krishna had in-form Suryakumar Yadav (5) caught behind.

De Kock also fell to Krishna in the 15th over before Lockie Ferguson thwarted Mumbai's progress by claiming the key wickets of Ishan Kishan (14) and Krunal Pandya (12).

Kolkata's brisk chase saw them move to fourth in the standings with eight points. Mumbai have the same points but slipped to sixth because of an inferior net run-rate to Kolkata and fifth-placed Rajasthan Royals.

Australian Associated Press