Schoolboy first-five Logan Blackburn did the best he could under pressure from bigger opponents charging up quick at first receiver, and reserve back Ioani Aki and reserve forward Dawson Sisson made some good carries when they came off the bench for the final quarter.
Well marked all night, second-five Dillon Adrole powered through three tacklers to score an excellent try on fulltime.
Not initially going to be involved in representative footy, veteran prop Viki Tofa answered the call and likewise came on late to help hookers Jack Yarrall and Kohlt Coveny, along with fellow prop Jack van Bussel in steadying a scrum that was getting monstered.
Manawatu's double try-scoring No. 8 Julian Goerke and rampaging flanker Dylan Hall dominated off the ruck with massive yards gained on the burst.
Showing an excellent passing game, Manawatu's other tries included fullback Jayden Keelan's mid-air dive at the corner flag, second-five Toroa Rapana running in off a tap-kick, and towering lock Ofa Tauatevalu busting two defenders on the line.
Reserve back Leyton Manuel took advantage of an ill-conceived chip kick from Wanganui's own 22m to snatch the bounce and outstrip the cover defenders to the corner.
Of course, local fans watching at Cooks Gardens got to play another game of "spot the expat", as Manawatu fielded former Wanganui age grade representatives and Collegiate 1st XV alumni in hooker Ben Strang, loose forward Jason Myers and goal-kicking first-five Te Atawhai Mason.
All three are high-powered personnel looking to take the next step in their careers – Mason and Strang were 2019 Hurricanes Under 18 camp attendees, with Strang going onto to represent NZ Secondary Schools, while Myers captained the NZ Heartland Under 19 squad.
The scoreline could have been higher if the difficult wind and rain had not kept Mason to one conversion from five attempts, while Manuel fared no better when he took over.
But given their makeshift nature and the horrible conditions, Development XV coach Carl Gibson couldn't fault his side's effort.
"Considering they're playing a whole lot of guys who are Academy, who have had three games together already, and been training for 4-5 weeks after they finished their club rugby, I thought our guys showed a lot of courage.
"One game and one training on Monday night, and then guys being injured and not around...you just have to work with what you've got."
Initially, three members of the 2020 Steelform Wanganui squad were going to play, however precautions on minor injuries meant only No8 Semi Vodosese took part and did both lineout jumping and carries off the ruck, with the ball like a bar of soap at times.
But without any other representative levels in a Covid-19 affected season, Gibson was content the teenagers from Senior rugby and Metro got at least one chance on a bigger platform.
"I actually think that's really good for Wanganui; those guys have chosen their clubs and they're loyal to their clubs [in Senior], but they still get an opportunity to come and have a crack.
"There's some good players in our team who stood up tonight; with a bit more go-forward ball they might have had a bit more opportunity."
Manawatu Academy 37 (J Goerke 2, J Keelan, D Hall, T Rapana, O Tauatevalu, L Manuel tries; T Mason con) bt Wanganui Development XV 17 (T Lennox 2, D Adrole tries; L Blackburn con). HT: 22-7.