On the eve of the second Test against India in Pune, he stayed true to his nickname and warmed up with a casual kickabout before wheeling away with his left-arm fingerspin at the nets.
There was an air of calmness around him even when he was engaging in some violent T20-style range-hitting towards the end of New Zealand's training session.
He would've been expected to do a job, even though he is only a sporadic presence in the Test team, pushed to the sidelines at home where conditions limit his skill. It might be fair to say now that he exceeded those expectations.
After going wide of the crease from left-arm around, Santner, who had originally started the second day by darting the ball into the surface, slowed his pace down to 82.6kph and had Kohli missing a swipe across the line.
There's a chance that Santner might not have played this game had offspin-bowling allrounder Michael Bracewell been available for selection. Before the Pune Test, Santner had a bowling average of 42.16 and a strike rate of 91.6.
He had taken some tap in the Tests against Sri Lanka in Galle and had never picked up a four-wicket haul in Test cricket, let alone a five-for. However, with a rough spot to work with, Santner kept hitting it with cunning pace variations and let the Pune pitch do the rest.
Santner kept attacking the stumps in India's first innings - six of his seven wickets were bowled or lbw - and he hopes to keep it just as simple in the final innings when the conditions could be even more extreme.