Sexton and coach Andy Farrell agreed Ireland still had lots of room for improvement.
“We need to keep our feet on the ground and keep driving this,” Sexton said. “There's a lot of young guys, very young — a lot younger than me — and they need to realize that this is still a start (to the 2023 Rugby World Cup) and we need to keep building.
“The great thing about beating New Zealand is that it gives a lift to the country but you don't win a trophy and you don't have something to show for it, as such. As happy as we are, we need to push on.”
The three-tries-to-two victory was launched and finished by an adopted New Zealander, winger James Lowe, who scored the opening try and stopped opposite Rieko Ioane in his tracks at the end.
Lowe had wanted to be an All Black since he was a kid, but when he thought he wasn't good enough he left for Ireland. He debuted a year ago but was dropped during the Six Nations. He was recalled this month after improving his defence.
“When I wrapped Rieko and we got the turnover, that was the moment,” he said.
“To be able to produce after 70 minutes against the best team in the world, that's what I'm happy about. I will thoroughly enjoy this.”
Lowe was one of several Irish facing the All Blacks for the first time, including another Kiwi in scrumhalf (and former Gisborne Boys' High School player) Jamison Gibson-Park, Ronan Kelleher, Caelan Doris, Jack Conan, Andrew Conway and Hugo Keenan but any nerves never showed.
The atmosphere was emotionally charged long before the match, and New Zealand's bid to put a lid on it early was undone by a yellow card to hooker Codie Taylor for a high tackle on Sexton.
Next minute, Ireland had a try. When the forwards couldn't punch the ball in, it came out and fullback Keenan made a last-gasp flick to Lowe to dive in.
Sexton missed the extras but Jordie Barrett nailed his first goalkick for 5-3.
A penalty against New Zealand's seven-man scrum was kicked to the corner, but Taylor arrived from the sin-bin to help them out of danger.
Not for long. Kelleher broke to the tryline and Furlong went over, but the try was cancelled after Kelleher was penalised for a triple movement.
Against the run of play, New Zealand reminded of their lethal ability; Dalton Papalii burst off Brodie Retallick's lineout take while the Irish expected a maul, and drew the last man to send in Taylor. Jordie Barrett converted as brother Beauden's exit for a head injury was confirmed.
Ireland responded. Lowe was stopped by Ioane short of the line and, again, the forwards couldn't get the ball in through 15 phases as the All Blacks pulled off a magnificent tryline stand. They got the ball back but didn't kick it out, and were besieged again until Gibson-Park couldn't hold a final handoff.
By halftime, the All Blacks somehow led 10-5 but sucked up 158 tackles to less than 40. The effort showed soon after halftime as Ireland made an extra metre in each tackle.
New Zealand's lead for 12 minutes evaporated when Kelleher went over for the tying try with a push from lock Iain Henderson. Sexton's conversion came off the post, but he converted after Doris fended off Taylor to break the New Zealand line and surge home.
Sexton's second penalty made it 20-10 near the hour but, again, New Zealand surprised.
Jordan chipped from his own half, Ioane regathered and sent Jordan to the line. Barrett converted.
Sexton, key in all three Ireland wins against the All Blacks, then went off after colliding heads with Ardie Savea and Carbery was introduced. His first penalty kick extended the gap to six — which became one when Akira Ioane scored. But Ioane's try was rubbed out after the last pass from brother Rieko was ruled forward. Barrett's consolation penalty closed the score to 23-20.
Cue Lowe, stopping Rieko Ioane, and Carbery from the halfway line.
Tadhg Beirne then trapped Jordan and Carbery's third penalty kick was the coup de grace.
“I was really impressed with them,” All Blacks coach Ian Foster said. “They were pretty polished.”
