Goals at either end of the first half sealed their fate, with their task made all the harder by a controversial penalty just before the break.
With young striker Dan Dryden unavailable, Nathan Stephenson was pushed forwards to lead the line. Callum Dobson returned in goal after duty with parent club Hebburn and Tafari Nicholas grabbed a starting place at wide right.
Redcar took charge with an opener in the third minute. Curtis Round converted with a close-range volley and he and his team-mates continued to press the visitors’ defence with their speed and movement.
Dobson was on top of his game again, making good stops from Round and Adam Boyes. Town kept their shape well and looked dangerous on the break.
But the game swung decisively in Redcar’s favour in the 40th minute when they were awarded a contentious spot-kick. Oscar Fletcher was alleged to have been fouled in the area, with the referee waving away Northallerton protests.
Craig Gott stepped up to convert the kick, which came at a crucial stage of the game to dent the visitors’ hopes of getting back into the game.
Manager Jason Newall introduced four second-half substitutes as Redcar tightened their grip on the contest. They added a third goal in the 82nd minute through Fletcher.
Redcar Athletic: Mazfari, Guru (Cann 88), Taylor, Liddle, Gott (Burgess 86), Lay, Anderson (Stott 90), Fletcher, Boyes, Fewster (Guy 88), Round (Priestley 73).
Northallerton Town: Dobson, Dale, Galbraith (Hume 46), Darville, Harwood, Allen, Stapley (Croft 63), Walker, Nicholas (Tew 63), Stephenson (Banks 72), Coatsworth.
Man of the Match: Adam Walker.