With three still needed to win off the final ball, it seemed that England skipper Eoin Morgan had left it too late against India at the Wankhede Stadium.
But the Irishman kept his cool, even after pacer Ashok Dinda controversially pulled out of the delivery first time round. The tactic though backfired for India as the Morgan struck a perfect straight six back over the seamer's head to tie the two-match series in Mumbai on Saturday.
Morgan stunning strike and his invaluable unbeaten 26-ball 49 helped the visitors snatch a nerve-wracking last-ball victory.
It was England's highest ever Twenty20 run-chase, and it saw them conclude their 2012 schedule with a win.
England required nine off the last over, thanks to the 26-year-old Morgan`s relentless onslaught that saw him smash five fours and two sixes.
Chasing a challenging target of 178, England were provided a blistering start by openers Michael Lumb and Alex Hales, who put on 80 runs for the first wicket in just over eight overs.
Lumb smashed 50 off a mere 34 balls while Hales made 42 off 33. But after their efforts, the show belonged to Morgan.
England needed 23 off the last two overs and managed 14 of them against Parvinder Awana.
The visitors, who opted to chase after winning the toss, were helped by a wayward Indian bowling attack and a shoddy fielding display that enabled the openers to score quick runs.
Apart from Lumb who hit six fours and two sixes - and Hales, who had made a quick-fire 56 off 35 balls in the first match, skipper Morgan and Jos Butler (15 off seven balls) contributed significantly to England`s successful run-chase on a good batting track.
For India, Yuvraj Singh was the lone bowler to succeed with another excellent spell of three for 17, following his match-winning effort of three for 19 in the first match at Pune where England lost by five wickets.
Yuvraj got the wickets of the two openers and Luke Wright (5), but did not get the desired support from the other bowlers. The worst performers were Awana and Piyush Chawla.
England would now depart for home before returning for the five-match ODI series, commencing at Rajkot on January 11.
Earlier, India recovered from a mid-innings stutter to post a challenging total of 177 for eight.
India got a rousing start was provided by Virat Kohli, who made a brisk 38 in 20 balls, while adding 57 runs with opener Gautam Gambhir (17) for the second wicket.
India lost their way a bit with the fall of four wickets between the seventh and 15th overs before skipper Mahendra Singh Dhoni (38 off 18 balls) and Suresh Raina (35 not out in 24 balls) provided the late spark with a sixth-wicket partnership of 60 in just 27 balls.
Among the other top-order batsmen, Rohit Sharma made a 19-ball 24, but Ajinkya Rahane and Yuvraj failed to deliver with the bat.
Opting to field, England bowlers started on a disciplined note before falling apart in the face Dhoni and Raina's late assault. They, though, fielded brilliantly right through.
Tim Bresnan was easily the best bowler with figures of one for 27 while Stuart Meaker leaked 42 runs.
Kohli hit seven fours and once he fell after making use of the power play overs, England took control with some brilliant out-fielding, before Dhoni and Raina wrested back the advantage.
Dhoni struck three fours and two sixes, both in one over of Jade Dernbach, while Raina hit three fours and a six.
When their turn to bat came, England commenced soundly though Hales was lucky to be dropped in the deep square leg region by Awana in the third over. He was on eight then.
Lumb started with a four and a six off Awana's first over and then smashed Ashwin straight down the ground for the first of his two sixes.
The opening duo helped England finish this period just ahead of India at 62 for no loss.
It was again left to Yuvraj to come to India's rescue with the ball.
Yuvraj broke the opening stand by having the 32-year-old South Africa-born Lumb stumped with a smart piece of bowling.
He struck again, with the last ball of his next over, trapping Wright leg before with a straighter one, that kept the Indian hopes alive.
He then packed off Hales in his fourth over, having the batsman slog-sweep to deep square leg fielder Dinda.
But none of the other bowlers rose to the occasion, with Awana and Piyush Chawla bowling several loose balls, much to England's liking.
Morgan, who could have been run out in the last over had not Dhoni missed the stumps with his underarm throw, was involved in valuable stands of 29 and 26 with Hales and Samit Patel, before completing the task with an unbroken association of 32 runs in 13 balls.
Awana, who also misfielded on a few occasions, gave away 42 runs while Chawla finished wicket-less after conceding 31. Ashwin, too, was expensive and was hit for 38 runs while Dinda gave away for the wicket of Patel.
England had earlier struggled to contain Mahendra Singh Dhoni and Suresh Raina's late onslaught and appeared to be up against it to better 177 for eight.
Virat Kohli and Dhoni top-scored with 38, while Raina was unbeaten on 35.
But on a good batting surface, and with a heavy dew making life difficult for India after Morgan had won an important toss, Michael Lumb (50) and then the captain himself scrambled England home.
Even another three economical wickets from Yuvraj Singh could not quite tip the balance India's way this time.