Chennai Super Kings 177 for 4 (Raina 73*) beat Royal Challengers Bangalore 175 (Kohli 70*, Bollinger 1-20) by six wickets
Scorecard and ball-by-ball details

How did Chennai win this? How did Bangalore lose this? Chennai always seemed to be lagging behind but surged like a tidal wave towards the end, with the odd run-filled over now and then, to storm into their third IPL final in four seasons. At the forefront was the feisty Suresh Raina, who pulled out the big shots through the latter half of the chase to set up an improbable win. The defeat makes Bangalore's path to the final - and beyond - tougher. They will have to win the second Qualifier on Saturday, if they are to meet Chennai in the final at the MA Chidambaram stadium, where the hosts have been unbeaten all season.

Bangalore will look back and rue at a few poor overs. There were full tosses and length deliveries galore and Chennai capitalised in some style. Virat Kohli bowled a slew of full tosses in the ninth over to leak 16 runs, and Abhimanyu Mithun kept bowling length deliveries in the 13th over, bleeding 23 runs. It included a fabulously carved six over the covers as Raina went down on a bent knee, to follow his muscled heave over long-off. Even then, the equation - 82 from 42 balls - seemed a tough proposition and it got tighter when it came down to 58 from 24. Chris Gayle had led from front with a parsimonious spell that read 4-0-19-0 as he fired in the skidders and the occasional yorker to pin down Chennai.

But Raina wasn't done yet, and he ramped it up style in the 17th over, from Zaheer Khan, who had been exemplary in his opening three-over spell. Raina's two sixes over midwicket, a thumping pull and a clubbed swing, were sandwiched by a bottom-hand powered six over wide long-on by MS Dhoni, who however fell in the same over. Zaheer went for 20 runs in that over and Chennai had well and truly seized the momentum.

More agony awaited Bangalore in the 19th over, bowled by S Aravind. Albie Morkel crashed a slower ball over long-on and clubbed a full toss over long-off before Raina killed another full toss over the midwicket boundary. That 21-run over left Chennai needing 12 off the final over by Daniel Vettori and Morkel dragged a four to wide long-on, before walloping the fourth ball over midwicket to win the contest.

Until those frenetic end overs, Bangalore were well on their way to becoming the first team to enter the final. The big question before the game was whether Bangalore would deflate like cheap party balloons if Gayle went out early. They answered that in an emphatic manner, as Kohli powered them to a competitive total.

Bangalore were in danger of slipping into free-fall after Gayle fell cheaply, trapped by R Aswhin, but Kohli and Luke Pomersbach ensured they stayed afloat. While Kohli batted with calculated aggression, Pomersbach counterattacked, taking 17 runs in the 15th over, off Dwayne Bravo. A murderous heave to wide long-on, a slash to third man and a flat six over midwicket were the highlights. Kohli, though, was the person who sculpted and shaped Bangalore's innings. Two shots in particular reflected the assurance in his knock. In the 13th over, he sashayed back to a back-of-length delivery from Raina to unfurl a peachy punch to the cover-point boundary. Then, off the final ball of the 16th over, he leaned forward to play a classy lofted whip over wide long-on Ashwin. He went on to produce two more screaming sixes - over long-on and covers - off Morkel in the 19th over, to push Bangalore to a good total but Raina decided to gatecrash the party.

Sriram Veera is a staff writer at ESPNcricinfo