Sehwag flattened the CSK attack with a 58-ball 122, which propelled his side to an imposing 226 for six after being invited to bat on a batting paradise at Wankhede stadium.
The Punjab side then survived carnage from Suresh Raina, who responded with a majestic 25-ball 87, as CSK managed 202 for seven in their chase.
The hand-eye coordination, which has got Sehwag thousands of runs in international cricket, was at work again as he punished the hapless CSK bowlers with utter disdain, smashing his way to the highest individual score of this season.
CSK skipper MS Dhoni shuffled his bowlers around but there was no stopping Sehwag, who entertained the Wankhede crowd with eight sixes and 12 fours.
Sehwag became only the second batsman this season to score a century after Mumbai Indians’ Lendl Simmons, who had scored an unbeaten 100 against Punjab only. And this is not first time Sehwag has scored a hundred in IPL, his first coming in 2011 for Delhi Daredevils against Deccan Chargers.
Punjab will now fight it out for the title with Kolkata Knight Riders on Sunday in Bangalore.
No team had ever chased a 227-run target in T20 history but Raina came up with an extraordinary knock which stunned the Punjab side and turned the match on its head.
Raina raced to second fastest fifty in IPL in just 16 balls when he lifted Sandeep Sharma over covers for a six.
In six overs, CSK were unbelievably placed at 100 for two with Raina batting on 87 from 25 balls with 84 of them coming in boundaries, 12 fours and six awe-inspiring sixes.
However, Raina was run out in the first ball after the power-play overs. Brendon McCullum called for a run but George Bailey found Raina short of crease with his direct hit.
One of the most regal innings in T20s met with a tragic end but it opened up the game and Chennai were back in the match after a forgettable effort with the bowl.
Raina’s dismissal though opened up the gates as wickets starting tumbling. Brendon McCullum (11) met with the same fate as that of Raina and Ravindra Jadeja (27) was caught brilliantly by Mitchell Johnson off Parvinder Awana.
David Hussey (1) fell in that same Awana over, leaving his skipper Dhoni with an unenvious task of scoring 84 runs from 42 balls. Dhoni has been an incredible finisher for his side but today his unbeaten 42 was not enough.
Earlier, it was not first time that Punjab tormented the CSK bowlers like this, since their previous highest score (231/4) had also come against the Dhoni-led side and it third time they have beaten CSK.
Sehwag put on 110 runs for the first wicket with Manan Vohra (34) and flattened the Super Kings bowling attack, which has conceded a score in excess of 200 for the third time in the season to the same opponents.
The swashbuckling opener’s pyrotechnics, when everyone expected Glenn Maxwell as the bigger threat, caught the two-time former champions by surprise.
No one was spared by the bespectacled Sehwag who looked unstoppable and completed his ton with a single in the 16th over off only 50 balls, the fastest hundred by any batsman in this Indian Premier League season.
Such was Sehwag’s domination of the Super Kings bowling that the smart knocks of Vohra, who hit 2 sixes and a four in 31 balls, and David Miller (38 in 19 balls) went into the shade.
Super Kings bled runs as their two lead spinners Ravichandran Ashwin and Ravindra Jadeja conceded 44 and 48 runs respectively. Paceman Ashish Nehra was the costliest by giving away 51 runs for the wickets of Sehwag and George Bailey. Mohit Sharma gave away 46 runs while Ishwar Pandey was the only bowler to concede under 40.
Kings XI got off to a blazing start after being asked to bat first on a good batting track. Both Vohra and Sehwag played shot after shot as the 50 was raised in just 26 balls before the scored jumped to 70 in six overs of power play.
In the next over by Ashwin, the discarded India opener swung the off spinner for a huge six over long on before completing his second half century of the season in 21 balls.
Sehwag greeted left arm spinner Ravindra Jadeja too with a slogged six over long on. The 100 of the innings came up in the first all of the 10th over by the end of which the score looked a very healthy 109 without loss.
Vohra miscued a pull shot and the skier was held well by Suresh Raina at short mid wicket to give Pandey and the harried Super Kings their first breakthrough in the 11th over.
When Nehra came off for his third over, Sehwag smashed his Delhi Ranji Trophy teammate for successive sixes over the straight field and 20 runs came off it.
Sehwag and Maxwell carted Ashwin over the straight field for a six each before the bowler had some consolation by having the latter caught in the deep.
Later Sehwag added 68 runs in 32 balls for the third wicket with Miller before hitting a full toss from Nehra to be caught at covers.
Punjab Innings – 226/6 (20 overs)
Batting Out Desc R B 4s 6s SR
Virender Sehwag c du Plessis b Nehra 122 58 12 8 210.3
Manan Vohra c Raina b I Pandey 34 31 1 2 109.7
Glenn Maxwell c Raina b Ashwin 13 6 1 1 216.7
David Miller run out (Dhoni) 38 19 5 1 200.0
George Bailey (c) b Nehra 1 2 0 0 50.0
Wriddhiman Saha (wk) c Dwayne Smith b Mohit Sharma 6 4 0 1 150.0
Mitchell Johnson not out 1 1 0 0 100.0
Extras 11 (b – 1 w – 8, nb – 1, lb – 1)
Total 226 (20 Overs, 6 Wickets)
Bowler O M R W ER
Ashish Nehra 4 0 51 2 12.8
Ishwar Pandey 4 0 35 1 8.8
Mohit Sharma 4 0 46 1 11.5
Ravichandran Ashwin 4 0 44 1 11.0
Ravindra Jadeja 4 0 48 0 12.0
Chennai Innings – 202/7 (20 overs)
Batting Out Desc R B 4s 6s SR
Dwayne Smith b Sandeep Sharma 7 11 0 0 63.6
Faf du Plessis c Bailey b Johnson 0 1 0 0 0.0
Suresh Raina run out (Bailey) 87 25 12 6 348.0
Brendon McCullum run out (Maxwell/W Saha) 11 16 0 0 68.8
Ravindra Jadeja c Johnson b Awana 27 21 2 1 128.6
David Hussey c Sehwag b Awana 1 3 0 0 33.3
MS Dhoni (c & wk) not out 42 31 3 3 135.5
Ravichandran Ashwin st W Saha b A Patel 10 11 0 0 90.9
Mohit Sharma not out 1 3 0 0 33.3
Extras 16 (b – 4 w – 6, nb – 2, lb – 4)
Total 202 (20 Overs, 7 Wickets)
Bowler O M R W ER
Mitchell Johnson 4 0 44 1 11.0
Sandeep Sharma 3 0 32 1 10.7
Parvinder Awana 4 0 59 2 14.8
Karanveer Singh 4 0 32 0 8.0
Glenn Maxwell 1 0 4 0 4.0
Akshar Patel 4 0 23 1 5.8