McCullum, man of the match after compiling an unbeaten 69 from 55 balls, skied a single off Irfan Pathan's last delivery to break the deadlock.
The scrambled run thwarted Pathan's late bid to single handedly drag the tourists into a contest that appeared beyond them after scoring 149 for six.
Pathan switched roles from whipping boy to potential hero when he removed Ross Taylor and Jacob Oram in consecutive balls in the 18th over to raise the possibility of a spectacular home side collapse.
The BLACKCAPS had eight wickets in hand when requiring 28 off the last 18 balls but the double breakthrough -- and Neil Broom's demise when he was caught by Pathan off Yuvraj Singh in the penultimate over -- left the game in the balance.
New Zealand needed 12 off the final over and the odds tipped in India's favour when McCullum's brother Nathan squirted a leg bye off the first ball.
The vice-captain then ran a single before regaining the strike and hitting the fourth and fifth balls to the fence.
With an elimination over looming, McCullum sliced the ball over a despairing Rohit Sharma as Pathan slumped.
McCullum, who marshalled New Zealand's seven wicket success in Christchurch on Wednesday with an unbeaten 53, struck eight boundaries and a solitary six -- to get off the mark against Pathan.
Earlier Pathan was collared for 18 off his second over as Jesse Ryder and McCullum amassed 33 off three overs.
Zaheer Khan ended a 53-run opening stand in the fifth over when he clipped Ryder's (26) off stump.
The introduction of Harbhajan Singh further stunted New Zealand's progress when he removed the in-form Martin Guptill leg before wicket for 10 despite the ball clipping an edge.
Guptill's departure at 69 for two in the ninth dovetailed with a relative lull as Harbhajan (1-15) and fellow spinner Ravindra Jadeja (0-21) applied the brakes.
A s ked to bat first, India produced almost a mirror image of the high risk approach employed in game one as Virender Sehwag continued his torment of Tim Southee.
Fresh from clubbing three consecutive sixes in game one, the opener took a trio of boundaries off the pace bowler.
But again his damage was limited when Iain O'Brien had the slugger mistiming gently to the New Zealand skipper at mid-off in the next over.
Sehwag's five boundary 24 took just 11 balls and six deliveries later Suresh Raina, the top scorer in Christchurch, was snaffled by Southee at mid on for duck when swinging Ian Butler across the line.
Yuvraj Singh assumed Raina's face-saving role, making the most of a let-off on 11 when Neil Broom dropped a skier while standing on the deep square leg boundary rope -- a glitch resulting in a six.
Singh brought up his half century in less anxious circumstances, slapping a long hop from Iain O'Brien into the crowd, but two balls later the fast bowler exacted revenge when Jacob Oram took a catch on extra cover boundary.
Singh, whose 34-ball cameo included a quartet of sixes, shared in a 45-run stand with captain Mahendra Singh Dhoni.
The pair succeeded in conserving wickets to the midway point of the innings but were well contained by Vettori (1-21) and Jesse Ryder's (0-18) nagging medium pace.
Yuvraj Singh eventually finished with a flurry -- taking consecutive sixes off Vettori -- but his demise in the 13th over with the score at 92 was swiftly followed by Yusuf Pathan when he was bowled by Vettori for a two-ball duck.
The onus was then on Dhoni, the Indian Premier League's most valuable player to cut loose, a task beyond the noted strokemaker.
D honi needed 18 deliveries to conjure up his first boundary and struggled with his timing and placement throughout a knock that realised an unbeaten 28 off 30 balls -- sluggish by Twenty20 standards.