A Waide Fairhurst brace either side of the break - the first an excellent 25-yard strike and the second a neat header - sealed the success and a place in the final against either Boston United or Gainsborough Trinity.
City included Luke Foster in the starting line-up with the trialist defender signing his registration forms prior to kick-off.
City: Farman, Gray, Newton, Foster, Brown, Fofana, Nolan, Fairhurst, Dixon, Tomlinson, Sheridan.
Subs: Boyce, Robinson, Wright, Jordan, Rowe.
Scunthorpe: Severn, Riberio, McAllister, Bateson, K Wootton, Waterfall, Adelakun, Howe, Grayson, Hornsey, J Wootton.
Subs: Smyth, Burdett, Cowling, Hare, Weaver.
Referee: Declan Ford
Attendance: 918 (176 visiting supporters)