The Wolfpack (3-1) scored touchdowns on five of its six drives in the first half to build a commanding 35-point halftime lead.
N.C. State quarterback Mike Glennon ran for two touchdowns and passed for one more. The senior completed 19 of 24 passes for 233 yards to lead N.C. State to its third straight victory after its season-opening loss to Tennessee.
Rashard Smith had a 73-yard punt return for a touchdown for the Wolfpack.
Cornerback David Amerson picked off Bulldog quarterback Aaron Miller for his third interception in as many games as N.C. State had its way with The Citadel (3-1).
Darien Robinson had a 65-yard touchdown run for The Citadel in the first quarter, providing the Bulldogs with their only highlight of the first half. It was The Citadel's fifth play this season that had gained more than 40 yards.
Robinson finished with 102 yards on nine carries. The Bulldogs rushed for 199 yards after coming into the game averaging 370 yards per outing.
N.C. State was without the three running backs who started the season at the top of the depth chart. Even with Mustafa Greene (suspension), James Washington (injury) and Tony Creecy (undisclosed) all unavailable, the Wolfpack managed to run for a season-high 284 yards, eclipsing the previous best of 127 against South Alabama.
Most of that came from Thornton's strong debut. The native of Hinesville, Ga., finished off the Wolfpack's opening drive with a 19-yard touchdown run where he showed nice vision in cutting back against the grain.
After Robinson took what looked to be a simple dive play and outran the entire Wolfpack defense, Thornton gave N.C. State the lead for good when he got into the end zone from 7 yards out on the Wolfpack's ensuing possession.
Thornton also had four catches for 26 yards.
N.C. State stretched its advantage to 21-7 when Bryan Underwood took a short pass from Glennon and turned it into a 20-yard touchdown reception. Underwood has scored a touchdown in all four of N.C. State's games this season.
The Wolfpack then took advantage of Glennon's two short touchdown runs in the second quarter and Smith's punt return to take a 42-7 lead at halftime.