"That was definitely the most intense game I've been involved in - it was up there with South Africa," Barrett said. "They are a tough nut to crack but they started to tire in the second half when we moved the ball around. We found the space."
Asked if he felt the Welsh were starting to crack in the second half, he said: "We could definitely see it in their body language and it was quite frustrating because we had a couple of opportunities that we didn't nail. We knew if we hung in there things would go our way."
Patrick McKendry: All Blacks power home
Barrett's performance, after he got the nod ahead of Aaron Cruden, will probably do little to halt the debate about who the All Blacks' best first-five is. Next year's Super Rugby season is looming as a fascinating one, with Dan Carter and Slade also having points to prove. Carter was clearly rusty in Edinburgh after his long lay-off, but Slade was one of the most consistent players on this tour.
The reality is the All Blacks are in an ideal position to have so many quality options.
"It will be a big Super 15 season for all of us 10s to play well and try to get a head start for that No10 jersey. It's fiercely contested so it's good for the All Blacks," Barrett said.
"I'm just happy at the moment to walk away with a satisfactory victory. I learned a lot from it, especially in the first half when things weren't going our way and we felt a bit of pressure."
Hansen was pleased with Barrett, who missed two shots at goal, but kicked a long one to draw level at 3-3 in an extremely tight first half.
Gregor Paul: All Blacks win all about character
"Goalkicking is tough," Hansen said. "We can all see when you miss. We take for granted the ones they get. He kicked some great goals ... I thought there was a point of difference when we had two five-eighths on the park. It allowed us to have two first receivers who could kick into the corners and turn them around and change the game up a little bit."
Barrett, who is looking forward to a break and a return to the Hurricanes under new coach Chris Boyd, said he practised his chip kicks in training but having one bounce into his arms was a slice of luck.
"It was one of those ones where you just run the line hoping for the bounce and it came my way so I was pretty happy."
OPTA MATCH STATS