The victory took Knight Riders to the third position behind Super Kings and Shakib Al Hasan's Sunrisers Hyderabad in the eight-team table with 10 points.
KKR chased down the score with 2.2 overs to spare and with six wickets in hands.
CSK players has only themselves to blame for the defeat which was a result of the combined effort of the trio of KKR's spinners - Sunil Naraine, Piyush Chawla and India regular Kuldeep Yadav - and the unbelievable batting display put up by the 18-year old Shubman Gill, who was India's vice-captain when the U-19 team lifted the ODI world cup a few months back.
The 18-year-old Gill started brilliantly, hitting Watson for three fours in an over, but displayed patience when KKR was four down for 97 in the 12th over. For Chennai, Harbhajan Singh bowled an economical spell of one wicket for 20 runs in three overs. Gill didn't slog it out but only played authentic cricketing shots in racing to his first 50 in his fledgling IPL career. "This boy is special", Dinesh remarked in his post-match talk. Karthik had won a good toss, grabbing the opportunity to protect the Knights from another famous chase by Chennai's big guns even as he put the visitors under pressure to put a big total on the board. Despite its winning streak, CSK hasn't been using its top five batsmen in the best possible manner, critics feel.
Australia's Shane Watson could only manage 11 with the bat but his Chennai Super Kings defeated the struggling Royal Challengers Bangalore by six wickets to be second in the Indian Premier League standing on net run rate.
"Dhoni will have to re-look the tactic of sending Faf du Plessis up the order for it means that the in-form batsman and orange cap holder Ambati Rayudu gets less overs to play".
CSK, which was at 121 for four, finally got some boost when M.S. Dhoni opened his arms in the 16th over.
CSK skipper MS Dhoni top scored with 43 runs from 25 balls.
U-19 star Gill was extremely pleasing on the eye and was in contention for the Man of the Match award for his breezy half century.