A minute earlier Carter missed with a drop goal off his right foot, but struck gold with his left with only seconds remaining in front of 21,000 spectators at AMI Stadium.
Having lost the first test in Auckland a week ago 42-10, the Irish were given no show in Christchurch, a city which hasn't experienced test rugby for almost two years.
But they dug deep, and led by their impressive forward pack, came within a sniff of victory. It would have been their first over the All Blacks in 107 years of trying and skipper Brian O'Driscoll didn't bother trying to hide his disappointment afterwards.
"It's difficult right now to see all the positives but when we look over the video I'm sure there will be plenty," O'Driscoll said.
"What a difference a week makes," Hansen said with a rueful smile afterwards. "I'd like to give Ireland a pat on the back for the way they played. I thought they played with a lot of control, energy and urgency.
"In saying that, I would also like to give my own side a pat on the back for the character they showed... there was special character there.
"We didn't play great but we showed some great character to win the game with a dropped goal."
He added: "It was a game we probably shouldn't have won but we showed some great composure."
In a sometimes spiteful match, All Blacks fullback Israel Dagg was sinbinned with eight minutes left for a late and high hit on fullback Rob Kearney.
From the resulting penalty, Jonathan Sexton missed a long attempt which would have given the Irish the lead.
Instead it was Carter who was the hero on a difficult night for New Zealand.
It was a much-improved performance from Ireland, the forward pack in particular played with a directness and intensity which troubled the All Blacks at the breakdown and in contact.
Julian Savea, who scored a hat-trick on debut in the comfortable win in Auckland last weekend, struggled under the high ball and the All Blacks' tight five were overshadowed by their opposites.
Make no mistake, the All Blacks were in a serious scrap in this match, literally at times, referee Nigel Owens speaking to Richie McCaw and O'Driscoll at tensions boiled over on the hour mark with the score 16-13.
The men in green were boosted by the return of injury of tighthead prop Mike Ross and loosehead Cian Healy also played well. A retreating All Blacks scrum late in the match was testament to that.
The All Blacks threatened to break free but just couldn't shake the Irish.
A sign of All Blacks anxieties was the sight of Carter attempting a drop goal after 58 minutes. They missed Kieran Read in the second half, the No8 injuring himself in one of his many carries, was substituted at halftime for Sam Cane.
Hansen said Read had suffered a head knock, the second in two weeks, but was okay. Fellow loose forward Adam Thomson went off in the second half with blood streaming from a nose he broke in training recently.
Ireland began strongly, in cold but still and dry conditions, maintaining possession and testing the All Blacks with rolling mauls.
Ill discipline from the home team was costly, with both props Tony Woodcock and Owen Franks penalised for leaving their feet at ruck time. Hansen said the constant stream of penalties was extremely frustrating for the coaches.
The first penalty put the Irish deep into All Blacks territory and the second led to their first try after 10 minutes to halfback Conor Murray. A rolling maul put the All Blacks' forwards on the back foot, with Murray slipping over from close to the line for a seven-pointer.
A Sexton penalty after 19 minutes put Ireland further ahead.
The All Blacks replied with renewed enthusiasm, Carter making a half break and Conrad Smith carrying strongly. Carter's penalty narrowed the gap.
The All Blacks threatened but passes refused to stick. Dagg made a break but his pass to Savea was wayward. Another two Carter penalties for ruck offences brought the All Blacks closer.
Carter had the chance to kick the All Blacks into the lead after the halftime hooter but his attempt from about 55m was just short. Moments earlier he had missed touch with a penalty which would have put his side hot on attack.
The All Blacks took the lead when Aaron Smith scored two minutes after the break when he was pushed over in a pile of bodies, Carter converting from near the sideline.
Sexton brought the Irish back to 16-13 with his second penalty.
Carter and Sexton added to their tallies, with the Irishman booting the Irish level at 19-19 with 11 minutes left to set up a thrilling finish.
The All Black had the final say on his home ground; the series clinched for the All Blacks in the toughest of ways.
All Blacks 22 (Aaron Smith try; Dan Carter con, 4 pens, drop goal)
Ireland 19 (Conor Murray try; Jonathan Sexton con, 4 pens)
HT: Ireland 10-9
