City were able to control the game with wise decision-making and their ability to open up the visitors' defence.
While the second half was somewhat of a less spectator-friendly affair, City were able to hold off any Redsox attacks.
As the numerical advantage fell to City after the red card, the hosts played smart football to make the game safe when midfielder Jordan Joblin-Hall slotted one home.
The earlier frustration was evident as before the match, Redsox were realistically the only side able to mount a serious challenge to PN Marist's league lead.
While Marist in fact lost 2-0 up at Taradale, which still gives Redsox a fighting chance, the reality is the Manawatu team will now have to rely heavily on other results and with points-based games running out, City have had the final say in the title chase to all intents and purposes.
For the locals, the only down side is they are sitting out the bye next weekend which in a way will stall their momentum. Nonetheless their next home outing, versus Team Taranaki, should provide good value for spectators and supporters alike.
No joy for Wanganui Athletic in the Western Premiership when they were undone 5-1 by Redsox Manawatu A's, and now find themselves in danger of being cemented to the base of the table if a turnaround in form can't be found in round two.
Results
Federation League: Wanganui City FC beat Redsox Manawatu 3-0.
Western Premiership: Redsox A's beat Wanganui Athletic 1sts 5-1.