The Under 12's would have rated their chances of success after staging a great fightback to recover from 12-3 down to reach 150-8 off 35 overs.
Having lost the normally reliable Sam Sheriff, Adam Lennox and Levi Woolston, and stalwart Joel Clark unavailable, Wanganui's recovery was led by Keithley Watson, who made 34 before retiring.
Kalvin Brown (24no) and Henry Deans (16no) showed great character, combining for a 40-run partnership for the ninth wicket, as coach Mark Godfrey credited the team's regular steward Jason Clark for drilling the squad on the importance of good running between wickets.
Manawatu never got their reply in as the heavens opened.
In the Under 13's game, it was the Wanganui bowlers who sparked the fightback to dismiss Manawatu for 134.
Going on and off due to the weather, after the initially success of getting both openers in the first 8 overs, Manawatu reached 100-2 from 20 overs, with the seam bowlers getting little assistance while fielding on a slippery outfield. Enter leg spinner Kieren McInnes, who after the second rain break bowled superbly to earn figures of 4-22 from 7 overs.
Conor Ingram and Beau Hourigan offered good support, as Manawatu were pressured into mistakes and lost their last 8 wickets for 34.
Wanganui were untroubled reaching 12-0 by the fifth over.
Stand-in captain Cameron Mackintosh showed very good leadership as Wanganui fielders helped stop Manawatu capitalise on their 3rd wicket partnership.