New Zealand completed the first perfect year of the professional era when they came from 19 points down to beat Ireland 24-22 thanks to a stoppage-time try in front of a heartbroken Dublin crowd.
On the verge of losing against the Irish for the first time in their rich history, Ryan Crotty's try and Aaron Cruden's conversion ensured the All Blacks became the first team to win all their matches in a calendar year since the game turned pro in the mid-90s.
It looked very different after 18 minutes when tries from Conroy Murray, Rory Best and Rob Kearney put the Irish 19-0 in front, the highlight of arguably the best 40 minutes an Irish team has ever played.
But tries from Julian Savea, Ben Franks and fellow replacement Crotty, together with Cruden's vital kick, knocked over at the second attempt after Ireland rushed out too quickly when he missed his first effort, made it 14 wins from 14.
"We weren't good enough in the end," Ireland flanker Sean O'Brien said in a pitchside interview. "Obviously the performance was a lot better but we still lost at the end of the day and we came here to win."
Ireland wanted a reaction after last weekend's dismal 32-15 defeat by Australia when they were outscored by four tries to none and they got exactly that when the recalled Murray gave them the lead after just four minutes.
They tore into the All Blacks from the off and Murray sneaked over the line after his forwards had set him up with a quick wave of gain-line breaking attacks.
Sexton, who passed a fitness test an hour before kickoff, added the conversion.
The Kiwis came right back and parked themselves on the Irish line but the home side's defence, exposed so easily a week ago, was up to the task to keep the belief flowing through the veins and two minutes later it was 14-0.
A sweeping move started and finished by Best, the hooker's clever pass to prop Cian Healy allowed the bruising Sean O'Brien some space and when the ball came back his way, Best gave the unlikeliest of dummies before diving over.
Ireland made it three tries in 18 minutes when Kearney intercepted the ball in his own half and ran untouched to cross the line as the home fans began to ask if this was really happening.
It was inevitable the All Blacks would get on the board and they got a try back when Cruden, starting for the injured Dan Carter, brilliantly dinked a ball through with his bad left foot for Savea to collect his 17th try in just 19 games.
Ireland did not lose any of their intensity and Sexton extended the lead with his first penalty before more fine defending left the score at 22-7 at the break.
New Zealand, who showed against South Africa in September that they are more than capable of mounting a comeback, took charge in the second half but were kept at bay with just a Cruden penalty to show for 13 minutes of relentless pressure.
It could have been worse had fullback Israel Dagg managed to touch the ball down when he crossed the line minutes earlier.
Cruden then scuffed a penalty attempt as Brian O'Driscoll's 128th and record-equalling cap ended in injury.
The visitors appeared rattled. The usually flawless Ma'a Nonu tripped up with nobody around him to cough up possession to the Irish as the clock ticked past the hour.
But the hosts were similarly ragged and although defending for their lives, they could hold out no longer as replacement Franks tumbled over for a try on 65 minutes and Cruden converted to cut the lead to just five points.
Ireland refused to fold as the noise around the ground turned deafening. A huge drive off a lineout gave a limping Sexton a shot to put New Zealand more than a score behind with six minutes to go. Crucially, he nudged it wide.
Ireland won the ball back and were less than 30 seconds away from seeing the game out but were penalised and New Zealand marched towards the Irish line.
It took a number of television replays to judge Crotty's try as fair and then Cruden's conversion ended Irish hopes of a first victory over New Zealand in 109 years as the All Blacks sealed their perfect year in the most dramatic of fashions.