Upcoming New Zealand U19 representative Nick Blundell, taking 2-33 and leg spinner Dominic Lock, with 2-22, were the pick of the bunch.
Heading out, Wanganui's reliance on Smith to keep a cool head was evident as he anchored several partnerships down the length of the batting order.
He found the boundary rope 11 times in a patient innings.
The innings folded mid-afternoon with the score at 281 all out.
Tellingly, after Smith the next highest contributions came from senior player Dominic Rayner (26) and young Henry Collier (22), while only two other batsmen reached double figures.
Hunting an outright win from a 91-run advantage, Wanganui struck early and often, with Rayner, Blundell and Brent Turner all picking up scalps to give their side a definite chance to force a result.