Santner ran out Shaun Marsh to secure the opening wicket on 44 as the opener tried to sneak two runs in the eighth over. He entered the attack in the 16th over and his first spell of six overs ended with one for 17. Parsimony prevailed despite his first ball going for four.
He lured Glenn Maxwell into a cut third ball. The delivery spun away and left the Australian all-rounder feathering an edge to wicketkeeper Tom Latham. The tourists' decision review was wasted in the process.
The coup de grace came when Eden Park hero Marcus Stoinis lofted a drive on 42 off 48 balls. Jimmy Neesham took the catch at long on in the face of the setting sun.
An eighth-wicket stand of 51 runs between Pat Cummins and Mitchell Starc brought Australia back into the contest, including 31 off Santner's final two overs. However, with 33 needed off as many balls, Cummins heaved a catch to Santner at mid-wicket. He didn't disappoint.
"A highlight was the way we thought on our feet with the ball, and with the bat we took it as deep as we could, finished nicely by Mitch," Boult said.
Captain Kane Williamson agreed.
"Mitch is a world-class bowler the way he controls his length and changes his pace. That makes life pretty difficult, even when batsmen hit with the wind to short boundaries. He's been world-class for us, pretty much every game in the shorter formats, which complements the fast bowlers."