Sunrisers Hyderabad suffered a second-straight defeat of IPL 11, as Kane Williamson's fine 84 from 51 balls wasn't enough to see them chase down Chennai Super Kings' 183-run target.
Chennai's Deepak Chahar (3-15) had incredible figures of 3-1 midway through his third over as Sunrisers - without injured opener Shikhar Dhawan - got off to a dreadful start, slipping to 22-3.
But Williamson, who moved up to the top of the order in Dhawan's absence, looked in fine form at the other end, cracking five fours and as many sixes to bring his side back into the game.
The Sunrisers skipper shared in a 79-run stand for the fifth wicket with big-hitting Yusuf Pathan (45 off 27 balls), reducing the required run-rate from up near 15-an-over to a more manageable 13.
But, Williamson fell to the final ball of Dwayne Bravo's 18th over, miscuing an attempted pull to midwicket, while Shardul Thakur accounted for Pathan at extra cover in the next to all but end the contest.
Rashid Khan (17no off 4) made a match of it by firing two maximums in the final few deliveries, but he couldn't find another when six was needed to win from the final ball - the Super Kings holding on for a four-run victory to take them top of the IPL.
Earlier, having been put into bat first, Chennai overcame a sluggish start which saw them manage only 54-2 from the opening 10 overs to post a massive 182-3 - Ambati Rayudu cracking a masterful 79 from 37 balls and Suresh Raina an unbeaten 54 from 43.
Chennai openers, Faf du Plessis (11) and Shane Watson (9) - fresh from a match-winning 106 in their last win over the Rajasthan Royals - failed to find a single boundary in the opening three overs and just as Watson swung six over deep midwicket in the fourth, he was out to Bhuvneshwar Kumar's next ball.
The Super Kings' 27-1 is the lowest powerplay score in this year's tournament, and things then got worse when Du Plessis fell to Rashid's first ball in the eighth over, out stumped.
But, Raina and Rayudu rebuilt and the Chennai innings finally sparked into life when Raina fired Rashid - who had another poor outing, conceding 49 runs - for back-to-back sixes in the 12th, while Rayudu took Billy Stanlake's 14th for 19 runs.
The partnership was only ended with a run-out, and a rather ridiculous one at that. Siddarth Kaul fumbled the throw in from Manish Pandey at long-off, leaving the pair in the middle looking to scamper for an overthrow that really wasn't there. Raina called Rayudu through, only to then send him back too late.
It didn't disrupt the Super Kings innings though - Raina easing through to fifty, while MS Dhoni (25no off 12) thrashed three fours and a six in a handy little cameo.
Sunrisers struggled badly at the start of their innings - Chahar picked up IPL-debutant Ricky Bhui for a five-ball duck in the opening over, Pandey in his second, and Deepak Hooda in his third.
Shakib Al Hasan hit a useful 24, from 19 balls, while Williamson eased to a sixth IPL fifty as Sunrisers recovered somewhat, but the required run-rate continued to climb.
With 88 runs needed from the final six overs, the Sunrisers charge came - Williamson smashed Sharma for three sixes in an over, while Pathan took two from Bravo's next.
But, death-bowling expert Bravo returned to take the crucial wicket of Williamson and just about defend the 19 needed from the final over to earn Chennai a fourth win in five.