Chahal hat-trick helps Punjab eliminate Chennai from IPL playoff race
Five-time champions Chennai made 190 all out after England's Sam Curran scored 88 off 47 balls but Punjab overhauled the total with two balls to spare.
Iyer stood tall with his 41-ball knock and put on a second-wicket partnership of 72 with impact substitute Prabhsimran Singh, who made 54.
"I love chasing on any field," said player of the match Iyer.
"I feel like I thrive whenever there is a big total on the board and you need to take the charge and momentum for the team for the rest of the batters to come and go full throttle."
Punjab climbed to second in the 10-team table as they hunt for a first IPL title.
The top four teams reach the play-offs, but bottom side CSK are already out of contention after suffering an eighth defeat in 10 matches.
Punjab were cruising to victory despite losing Prabhsimran and then Nehal Wadhera to fall to 136-3 in the 15th over.
Iyer picked up the pace alongside Shashank Singh, who made 23.
But the Kings stuttered late on after Iyer was bowled by Sri Lanka bowler Matheesha Pathirana to leave three required from eight balls.
The dismissal of Suryansh Shedge with one needed in the final over, followed by a dot ball, created some late excitement at Chepauk stadium, but Marco Jansen inside edged Khaleel Ahmed for a boundary to seal his team's sixth victory of the campaign.
Leg-spinner Chahal's four wickets in the penultimate over of CSK's innings -- including the IPL's first hat-trick since 2023 -- proved crucial as the hosts were bowled out in 19.2 overs.
Earlier, Chennai lost three early wickets, including Ravindra Jadeja for 17 in the sixth over, before Curran and Dewald Brevis, who hit 32, put on 78 runs for the fourth wicket.
"it was the first time we put enough runs on the board," said skipper M.S. Dhoni.
"But was it a par score? I feel slightly short. Yes, a bit demanding from the batters but I feel we could've got slightly more."
Afghanistan all-rounder Azmatullah Omarzai broke the stand by bowling Brevis before Curran reached his fifty.
Curran's score was the highest by any Chennai batter this season as the England all-rounder hit nine fours and four sixes.
He was finally dismissed by South African left-arm quick Jansen before Chahal took centre stage.
Chahal sent back the 43-year-old Dhoni after being hit for a six by the Chennai captain.
The India international then took the wickets of Deepak Hooda, Anshul Kamboj and Noor Ahmad to claim his second and the 23rd IPL hat-trick since its inaugural season in 2008.