Kolkata Knight Riders' hopes of a third IPL title remain intact after Dinesh Karthik, Andre Russell and their spinners helped them dump out Rajasthan Royals with a 25-run win in the eliminator.
Karthik (52 off 38) and Russell (49no off 25) propelled Kolkata, champions in 2012 and 2014, from 51-4 to 169-7 at Eden Gardens, with Rajasthan only able to muster 144-4 in reply, despite Sanju Samson's 50 from 38 deliveries, as Piyush Chawla (2-24) and Kuldeep Yadav (1-18) proved too frugal.
Samson's departure in the 17th over with 44 runs required proved crucial with Rajasthan, whose sole IPL title came in 2008, exiting the tournament.
KKR will battle Sunrisers Hyderabad at Eden Gardens on Friday with the winner going on to face Chennai Super Kings in Sunday's final in Mumbai.
Kolkata, who finished third in the league phase, one spot above Rajasthan, lost three wickets in the first four overs, with off-spinner Krishnappa Gowtham (3-15) removing Sunil Narine (4) second ball, having seen the West Indian club his first delivery for a boundary through cover.
Gowtham caught and bowled Robin Uthappa (4) off a leading edge in the third over, before Jofra Archer (2-33) - Rajasthan's sole 'English' star with Jos Buttler and Ben Stokes having returned home for Test duty - had Nitish Rana (3) pouched at midwicket with just 24 on the board.
Chris Lynn (18) then fell in the eighth over but Karthik revived the innings, firstly with Shubman Gill (27) - the Kolkata skipper putting on 55 with Gill before the teenager was dismissed by Archer - while Russell slammed five sixes in his knock as KKR racked up 87 from the final seven overs.
New Zealand leg-spinner Ish Sodhi (0-15) was the most economical of the Rajasthan bowlers with Kolkata unable to hit a solitary boundary off him - and slow bowlers also proved key for KKR during the Royals' run chase.
Chawla had Samson caught in the deep as the asking rate increased, shortly after Kuleep ousted Royals skipper Ajinkya Rahane (46) to end a second-wicket stand of 62 with Samson.
Kolkata were out of spin once the 17th over was completed but pacemen Prasidh Krishna and Russell did not let the position slip as KKR earned a winner-takes-all showdown with Sunrisers.
Watch Sunrisers v Kolkata in the IPL qualifier, live on Sky Sports Mix from 2pm on Friday.