All Blacks switch to play-offs mode
New Zealand now await the outcome of the Ireland-France game at Cardiff on Sunday (NZT) to learn which will be their quarter-final opponent in Millennium Stadium next weekend.
The All Blacks will play the loser of that game.
New Zealand transfer to Swansea on Sunday to begin their preparation for the quarter-final.
All Blacks captain in Newcastle on Saturday Kieran Read said Tonga, who were beaten 47-9, had given the side a tough game which was what they needed at that stage of the tournament .
"Obviously there are things we can work on," Read said.
"[In] the first half they put us under a lot of pressure. It is going to be like that next week. In some ways we fought back really hard and I'm glad we got some points in the second half.
"They're a great side when they want to throw the ball around and they took us on up front. We're really pleased the way we stuck at it, [when he was in the sin-bin either side of half-time] they put some pressure on our scrum but we held our line there."
Read said in the quarter-final New Zealand had to be prepared to turn up for a do-or-die battle.
"Certainly our work up front needs to probably improve, especially in that first half but we'll regroup, we're glad to be where we are. Not everyone's there next week so we're looking forward to that challenge," he said.
Tongan captain Nili Latu said: "We came into this game today wanting to attack the All Blacks and we felt at times we were in the game but it shows we made too many mistakes in defence.
"I can't think my boys enough, definitely we gave it our all tonight.
"We believed we had to come out in the second half firing but playing the No.1 team in the world we can't afford to make mistakes," he said.
Coach Steve Hansen was happier with the performance but acknowledged after the game there was still work to be done by the side as they continue their tournament build-up in Swansea.
"It wasn't complete but the second half we are pretty happy with. We were a bit scratchy with the first half but very, very happy with the way we finished off the game. I thought the guys coming off the bench added.
"We can put a fullstop on the roundrobin and now we're off to the finals so it's finals footie coming up and we'll look forward to that.
"We can't afford to make unforced errors, we'll look at that and just keep building on our game. We'll try and improve our skill execution and our set piece execution and right across the board we'll look to improve," he said.
Nehe Milner-Skudder, who scored two tries and laid on Ma'a Nonu's try in his 100th Test, was named man of the match said the side were 'pretty happy' with the result.
"Tonga really brought it to us in that first half and we really made hard work for ourselves but the way we came out in the second half and managed to get into our game plan things came together quite nicely so we're pretty happy with that," he said.
"The knockout stage is coming up so we've got to be on our game otherwise we'll be going home."
Nonu was presented with his 100-game cap by team captain Richie McCaw after the game.
Nonu said afterwards he was happy to seal the game with a try, his 30th in Tests.
"It was a bit of a scratchy start as Tonga came at us defensively in the first 20 minutes. We tried to put some phases together but there were a few errors in the first half," he said.
However, things had improved in the second half.
"It's hard to play Tonga, they're a physical side and all credit to them."
He said the finals side of the tournament was 'wait and see' but it was real rugby now and the first final would be next week.