Ravindra Jadeja struck a big blow to Kolkata Knight Riders' Indian Premier League play-off hopes with a swashbuckling knock to seal a dramatic six-wicket win for Chennai Super Kings.

KKR would have moved above Kings XI Punjab into fourth place with a win in their penultimate match of the regular season in Dubai on Thursday, but they were beaten by bottom side Chennai.

Nitish Rana made a magnificent 87 off 61 balls to get KKR up to 172-5, spinner Jadeja taking 1-20 from three overs and Lungi Ngidi 2-34.

CSK were going along well with Ruturaj Gaikwad (72 from 53) and Ambati Rayudu (30) putting on 68 for the second wicket, but slipped to 140-4 after losing three wickets for 22 runs.

Pat Cummins (2-31) and Varun Chakravarthy (2-20) had KKR scenting victory, the Australia paceman having cleaned up Gaikwad and MS Dhoni falling for only one.

The Super Kings needed 30 off 12 two overs, but Lockie Ferguson conceded 20 off a nightmare 19th over and Jadeja (31 not out from 11) clattered the penultimate ball of the match from Kamlesh Nagarkoti for six before sending the last delivery beyond the ropes when just one was needed to win.

Back-to-back defeats have left KKR with their fate out of their hands ahead of a showdown with Rajasthan Royals on Sunday.

RANA RAISES THE TEMPO

KKR got bogged down in the middle of their innings as the Super Kings spinners gave little away after Karn Sharma uprooted Shubman Gill's leg stump.

They were 93-3 when Rinku Singh fell to the impressive Jadeja off the fifth ball of the 13th over, but Rana hung around to take them up to a competitive total.

KKR took 66 off the last five overs, Rana shifting through the gears after reaching his 50 off 44 balls and hitting four sixes in a quality knock, with Dinesh Karthik adding a brisk unbeaten 21.

LOCKIE LAPSES COST KKR

With the excellent Gaikwad still in the middle and 53 needed off six overs, it seemed to be advantage CSK but they could only take eight off the next two overs and Varun accounted for Dhoni.

Varun also dropped Sam Curran – who finished unbeaten on 13 – before he was off the mark, but it was the return of Ferguson that proved to be the most costly, the paceman bowling a wide and then a no-ball that cost three runs.

Jadeja added insult to injury by launching the resulting free hit for six and struck Ferguson's final ball to the boundary to leave KKR needing 10 off the last over.

Nagarkoti gave KKR hope by conceding three off four balls, but Jadeja was in the mood, hitting him over midwicket for six and blasting the last delivery over wide long-on to floor KKR.