Boult, who took wickets with his first two legitimate deliveries, and Southee will damage other far better batting lineups. Right now they are as good as any opening pair going around.
Corey Anderson, with three wickets for four in the space of 16 balls, enhanced his "golden arm" standing. Dan Vettori winkled out three for none in four balls at the end of the innings.
Apart from a gritty and impressive 97-run stand for the fifth wicket between half century makers, stocky Matt Machan, of Sussex, and Pretoria-born Richie Berrington, there was little to savour for the Scots in the first half of the match.
The second, however, was another story. Their bowlers ran in hard and got good rewards. But several New Zealand shots were witless. Even Kane Williamson, with his deep-seated love of occupying the crease, ran down the pitch and had a heave at the ball to give wicketkeeper Matt Cross one of his four catches.
Iain Wardlaw and Josh Davey prospered from New Zealand's sloppiness. However Boult, flanked by an entourage of four team officials, wasn't about to get down on his batting teammates.
"I reckon the Scots bowled really well," he said. "They gave it everything and put some decent pressure on us. But I don't think we will be too fazed as a batting unit.
"It was a little scarier than we wanted, I guess. When I'm rushing around the changing room trying to chuck the pads on it means we might be in a bit of trouble.
"But we got there in the end, so it's pretty satisfying."
Boult's point about the Scots is a fair one but New Zealand were collectively guilty of wasting a chance for what could have amounted to a good middle-wicket workout.
Machan, a David Warner lookalike and with the pugnacious strokeplay to match, and Berrington, who hit a 56-ball 100 in a T20 win over Bangladesh a couple of years ago, ensured the bowlers didn't get it all their own way.
However, New Zealand's outfielding was again top notch, while the Scots will be grumpy at shelling two chances in the deep. That's an aspect they pride themselves on.
Their captain Preston Mommsen suggested his bowlers had shown New Zealand can be vulnerable "if you are able to keep them under pressure, and put the ball in good areas, as any batsman is. Chasing a small total might have been a little tricky for them and they changed their natural game."
He admitted Scotland had no answer to Boult and Southee early. As a contest the mates from Northern Districts appeared to have knocked Scotland irretrievably sideways.
New Zealand's batsmen then conspired to hand them a lifeline.
3 things out of the game
• You should learn from every match, so call the Scotland game a timely reminder for New Zealand's batsmen. Eye on the ball chaps.
• Anderson and Broad; Steyn and Morkel; Johnson and whoever. Trent Boult and Tim Southee rank with the very best right now.
• What chance an unchanged XI for a third straight game, against England on Friday? Wise money would suggest yes, despite the wonky batting effort yesterday.
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