The loss, by a huge 98-run margin, has pushed LSG out of the top four with the playoffs not far away.
Fiery spells from Jadeja, Deshpande help Chennai beat Punjab by 28 runs.
RCB lost six wickets for only 25 runs in the chase after a strong start, but Karthik and Swapnil counterpunched to complete the win.
Cummins bowled a superb 19th over followed by Bhuvneshwar successfully defending 12 in the final over.
The spinners combined for eight boundary-less overs that fetched them four wickets for just 33 runs.
Marcus Stoinis once again rescued a win as Lucknow Super Giants emerged triumphant with a four-wicket win against Mumbai.
The target of 154 runs was a cakewalk for KKR as the Kolkata batters chased down the total in just 16.3 overs.
Chennai Super Kings move to third on the points table but are tied with four other sides on ten points.
A fiery 41-ball century by Will Jacks and Virat Kohli unbeaten 70 runs helped Royal Challengers Bengaluru to a 9-wicket victory over Gujarat Titans.
The unbeaten blistering 121-run partnership between Sanju Samson and Dhruv Jurel powered Rajasthan Royals to a 7-wicket victory over Lucknow Super Giants on Saturday.