Dwayne Bravo slammed a six off the last ball to help Chennai Super Kings seal a five-wicket victory over Kolkata Knight Riders.
Chasing 159, an opening partnership of 97 from Mike Hussey (56) and Murali Vijay (36) seemed to put Chennai on course for a comfortable victory.
However Sunil Narine, who finished with figures of 2-14 from his four overs, dismissed the duo in the same over to give the Knight Riders some hope.
Captain Mahendra Singh Dhoni's 28 off 21 balls helped the Super Kings remain on course, though they still needed five from the final delivery.
Bravo duly delivered the maximum they required, launching Rajat Bhatia over the long-on boundary to help his side maintain their play-off spot in the Indian Premier League table.
The Knight Riders had earlier been indebted to skipper Gautam Gambhir for posting a challenging total of 158-6 from their 20 overs.
The India international hit three sixes and six fours to top score with 62, sharing an opening stand of 99 with New Zealander Brendon McCullum (37).
But when the pair departed in successive overs, the hosts somewhat lost their way at Eden Gardens, even with Debabrata Das blasting an unbeaten 19 in the closing stages.
Shadab Jakati was the pick of the Chennai attack, Gambhir one of his victims as he finished with 2-26. There were also wickets for Ben Hilfenhaus, Ravi Ashwin and Ravindra Jadeja, with McCullum being run out.