Nitro fumbled on its third possession, leading to a 6-yard TD pass from Grier to Kevin Forrest and an 18-0 advantage.
"We had a few mistakes early with a blocked punt, an interception and a fumble and all three of them turned into points for them," said Nitro coach Derek Midkiff. "That's a really good football team and when you make mistakes early like we did, they're going to jump all over you."
The Black Eagles stretched their lead to 25-0 when Grier connected with Fred Crozier from 7 yards out with 11:45 before the half.
SC stretched its halftime lead to 31-0 on a 69-yard pass from Grier to Marquel Hampton midway through the second quarter.
The start of the second half was just as ominous for the Wildcats when Black Eagles junior B.J. Moore returned the opening kickoff 75 yards for a score to stretch the advantage to 37-0.
Chrisjamar Perkins closed out the scoring in the third quarter with a 28-yard scamper to make it 44-0. The final Black Eagle score came on a 33-yard run by L.K. Richmond with 11:01 to play.
Nitro finally got on the board in the fourth quarter on touchdown runs of 37 and 12 yards by Brayden Underwood. Underwood paced Nitro with 162 yards on 31 carries, while Nick Brown added 64 yards on 13 tries.
The competition stiffens for South Charleston next Friday when it hosts Capital at 7:30 p.m. Nitro travels to cross-river rival St. Albans, also at 7:30.
Contact Michael Dailey at mike.dai...@dailymail.com. Follow him on Twitter @MichaelDaileyWV.