Chasing a paltry 120, the Super Kings found themselves on a tight corner when they were redused to 89 for six in the 17th over.
But Jadeja (36 off 14) meant business and used his long handle to great effect to wrap up the issue for CSK. He shared an unbeaten 35-run partnership with Dwayne Bravo (7) to guide CSK home.
Apart from Jadeja, Mike Hussey (40 off 51) played a sensible innings at the top to keep CSK in the hunt even thought wickets kept falling at the other end.
With CSK needing 27 runs from the last three overs, the Knight Riders brought in their trump card Sunil Narine in the 18th over, but Jadeja hit the bowler straight over his head for a huge six.
Jadeja got a huge reprieve when Yusuf Pathan dropped him at the square leg boundary as he continued his assault with three boundaries in Kallis` penultimate over that reduced the equation to two runs from the last over.
Jadeja was in no mood to relent even though the game was under their control. He pulled Pathan over midwicket boundary for another six to help the Super Kings wrap up the issue with five balls to spare.
Like Knight Riders, the Super Kings had a surprise up their sleeve when they sent Ravichandran Ashwin (11) to open the innings along with Hussey. But the move failed outrightly as the visitors had a sloppy start to their low chase.
Narine gave KKR breakthrough in the fifth over, dismissing Ashwin while Senanayake, who opened the proceedings with Balaji, ran through his four overs and gave the team their second wicket in the form of Murali Vijay (2).
The Super Kings were reduced to 40 for three by the ninth over as Suresh Raina (7) continued his miserable outing.
Just when Hussey and Dhoni were beginning to get going, Morgan dismissed the Super Kings skipper with a brilliant run-out.
In fact, at the second break (strategic time out), the Super Kings were in a spot of bother with 50 runs required from the last five overs with six wickets in hand.
Hussey finally broke the shackles when he despatched a Kallis length ball over deep square leg boundary before Jadeja spanked Balaji over his head in the very second ball he faced.
Earlier, the Knight Riders frittered away a good start to be restricted to a modest 119 for nine.
Opting to bat, the Knight Riders gambled with Yusuf Pathan, who was sent to open the innings along with skipper Gautam Gambhir.
The duo, however, did not disappoint and gave the Knight Riders a flying start sharing 46 runs off just 35 balls before losing the Chennai outfit turned things around.
After Gambhir (25) was dismissed by a stunning Hussey catch, the Knight Riders batsmen committed a hara-kiri of sorts as, from 46 for no loss, they slumped to 91 for eight in 15.5 overs.
It was `mystery man` Narine`s six-ball 13, which had two big sixes, that helped the Knight Riders cross the 100-run mark.
For the Super Kings, Jadeja returned with figures three for 20 from his four overs, while Aswhin scalped two wickets for 21 runs.
Fresh from three consecutive half-centuries, Gambhir started positively to pick up 11 runs off the first over,
Pathan too looked positive and smashed rookie Mohit Sharma for two boundaries as the Knight Riders made a brisk start.
It took a brilliant diving catch from Hussey to sent packing Gambhir and break the dangerous-looking partnership.
With the fall of Gambhir`s wicket, panic started to grip the Knight Riders` ranks as they were soon reduced to 55 for four.
In the first ball of the next over, Jacques Kallis departed without even facing a ball, courtesy some sloppy running between the wickets from the experienced batsman as Subramaniam Badrinath caught him short off the crease with a direct hit.
The Super Kings had another prized scalp in Eoin Morgan (2) when Dwayne Bravo dismissed the Englishman in the next over.
Pathan followed suit. He was caught short of the crease while going for a double as Super Kings picked up KKR`s fourth wicket in a span of just 13 balls.
Soon the Knight Riders worst fears came to fore as wickets fell like nine pins. There was little contribution from the home team`s domestic talents, who did not show any application.
Manoj Tiwary (13) capped yet another poor outing, while Debabrata Das (19), Rajat Bhatia (1) and Laxmi Ratan Shukla (1) contributed little when it required the most.
Chennai captain Dhoni smartly operated his spin duo of Ashwin and Jadeja as the duo ran through Kolkata`s late order.
Ashwin had a wicket maiden over when he scalped Tiwary, while Jadeja took two wickets (Bhatia and Shukla) in the next over as the Knight Riders looked in danger of being bundled out inside the three figure mark.
It was Narine`s big swings that took the Knight Riders past 100 before the West Indian became Jadeja`s third victim.