United didn't waste any time extending their lead following the break. Gore turned provider for the third, playing a well-weighted pass for Moorhouse to run onto, which he did, slotting his finish around an onrushing Mohamed.
Gore had involvement in the fourth, too, this time teeing up Wheatley to curl a shot beyond the grasp of the Saints' gloveman just short of the hour mark.
Simon Rusk's side did manage to reduce their arrears shortly after Wheatley's goal, with a smart delivery from Brandon Charles finding the head of Baylee Dipepa, but it would prove too late for the visitors to mount a comeback.
The young Reds signed off in style thanks to Moorhouse, whose snaking stoppage-time run inside the box allowed him to add his second, United's fifth and the final goal of the afternoon.