The league leaders were roundly thrashed as Ravel Morrison and Will Keane hit a pair apiece and Ryan Tunnicliffe also tucked away a neat finish, while scores of other opportunities went begging.
Morrison opened the scoring and Keane doubled the Reds' lead just before the interval. The striker then missed a penalty early in the second period, shortly before Michael Richardson pulled a goal back for the Magpies.
United continued to create the greater openings, however, and Morrison powered in his second before Tunnicliffe slotted home a finish and Keane headed home from close range in injury-time.
Newcastle's sketchy defending - unaided by an insistence on playing a high defensive line - made for countless opportunities for the hosts. The opener from Morrison, however, was barely a half-chance.
The tricky attacking midfielder's initial pass to Tunnicliffe had been intercepted, but he reacted quickly, fashioned space and hit a low, early shot fractionally inside Ole Soderberg's near post.
As United dominated, Marnick Vermijl shot just wide with Soderberg rooted, while the young stopper had to be alert to pip Keane to Magnus Eikrem's lofted pass in a closely contested foot race.
Keane took his customary place on the scoresheet shortly before the interval. Eikrem's corner was flicked on by Tunnicliffe, and the unmarked Keane gently half-volleyed home a simple finish.