But they also came under enormous pressure in the final 30 minutes as Samoa battered them physically and scored four tries in 11 minutes to eat into the Kiwis' lead. It was fortunate Samoa struggled to kick their goals (two from five) or it could have set up a very tight finish.
The Kiwis tried to match Samoa's physicality in that period, which is a key feature of their game with so many big forwards, but were often overrun and struggled to reassert themselves when they did have the ball.
"I wouldn't say it was embarrassing," coach Stephen Kearney said. "I think it was disappointing. The Samoan side played with a lot of energy and enthusiasm through that period and put some tries on us. We dropped some balls and they gained some momentum. We didn't see a great deal of possession for 20 minutes.
"There were some good parts of the game for us. When we stuck to our structures and processes, we built some really good pressure and came up with some pretty good plays."
Winger Manu Vatuvei scored a hat-trick and captain Simon Mannering got a couple as the Kiwis ran in eight tries.
Props Jared Waerea-Hargreaves (162m) and Jesse Bromwich (106m) also found some good territory, especially in the first half, and centre Dean Whare continues to impress early in his international career.
Another positive was the fact they emerged with seemingly little collateral damage from such a brutal encounter. Vatuvei picked up an ankle injury early in the match but played on and Frank-Paul Nu'uausala was left dazed after a head knock.
Both could well be rested for the Kiwis' second match against France in Avignon on Saturday morning (NZT), particularly as it's a short turnaround. Kearney has previously said Krisnan Inu will play against France and the likes of Greg Eastwood, Jason Nightingale, Ben Matulino and Thomas Leuluai are likely to come into the frame.
Both Australia and England, their two main rivals in the tournament, were similarly scratchy and New Zealand traditionally get better as a tournament goes on. They should comfortably beat France and Papua New Guinea in their final two pool games and the games aren't likely to be nearly as physical, which should allow them to find some rhythm.
France beat PNG 9-8 yesterday morning, although PNG blew a golden chance to win when fullback David Mead missed a late penalty from in front of the posts.
The Kiwis, however, will be more interested in fixing up their own problems.
"[Samoa] played very well but we've got to be disappointed with the way we defended,'' Mannering said. "It's obviously not a good enough performance to carry on in this tournament. Hopefully it gives us a shot in the arm.''
New Zealand 42 (Manu Vatuvei 3, Simon Mannering 2, Josh Hoffman, Roger Tuivasa-Sheck, Issac Luke tries; Shaun Johnson 5 gls) Samoa 24 (Ben Roberts, Joseph Leilua, Penani Manumeasili, Suaia Matagi, Anthony Winterstein tries; Roberts 2 gls). HT: 22-4.
