He would also take the last wicket to finish with figures of 4-17. Wairarapa never recovered in the face of some accurate bowling and aggressive fielding.
Captain Quinn Mailman was the next best bowler with 2-7, as the visitors succumbed on 107.
Conor Ingrams made two well-taken catches, which proved crucial.
The win means Wanganui U13 have won seven of nine completed games this summer.
The Under 12s were missing four regular players as the Hunterville team was away on a cricket tour, while the school has having orientation for their new students.
Coach Jason Clark told the side to build pressure by bowling a good length and forcing Wairarapa batsmen to take risks. It worked well as economical bowling offered up chances for run outs, with Ben Strang leading the way with a direct hit on the stumps while also being committed on the boundary.
Wanganui held the visitors to 117-8, with Conrad Slako taking 2-20 five overs, Joel Clark 1-12 off seven overs, including maidens off his first four, and Harry Godfrey 0-5 off four.
The bowlers and fielders having done their job, the batsmen took over as Wanganui waltzed through to 118-1 in the 17th over.
Levi Woolston (30no) and Sam Sherriff (retired 50) ran singles well and put the bad balls to the boundary.
