On the night before his team’s biggest game of the season, South County senior Devin Vandyke showed up for work at Best Buy at 10:30 p.m. for a Thanksgiving night shift and stayed until 2:30 a.m. before heading home.

He got just three hours of sleep and then reported to the Stallions’ locker room at 7 a.m. Friday to trade his blue work uniform for a white South County jersey.

That afternoon, the Virginia Tech-bound linebacker made it a Black Friday for No. 10 Yorktown, registering three sacks, a forced fumble, a fumble recovery and two blocked punts to lead the 13th-ranked Stallions to a 37-13 win in Arlington and give the Lorton school its first Virginia AAA Northern Region Division 5 championship.

South County (10-3) will host a Division 5 state semifinal on Dec. 3 against the winner of the Central Region final between Hanover and Atlee.

Following a week of practice in which Stallions Coach Gerry Pannoni said an under-the-weather Vandyke had struggled, the standout certainly didn’t inform his coach he would be working the late shift the night before a 1:30 p.m. kickoff.

“No, I didn’t tell him,” Vandyke said, chuckling. “I guess he’ll find out when he reads his paper tomorrow.”

Pannoni would have little to complain about. With Vandyke leading the way against Yorktown (12-1) — which entered the game undefeated and averaging 41 points per game — South County’s defense continued its phenomenal play.

The Stallions’ starting unit did not surrender a touchdown — it has yet to do so in the postseason — and forced three turnovers along with the two blocked punts.

Holding a 3-0 lead late in the first quarter, South County linebacker Oren Burks caused a fumble that Vandyke recovered at the Yorktown 39-yard line. Six plays later, quarterback Shane Foley plunged in from one yard to make it 10-0.

Vandyke blocked his first punt with 25 seconds left in the half, giving South County the ball at the Patriots 18-yard line, and the Stallions needed just two plays to increase the lead to 17-0.

“We average about four turnovers a game,” senior defensive back Andrew Rector said. “They help us out; if our offense is struggling, we can put points on the board, too.”

In the fourth quarter, linebacker Timmy Hunt’s 65-yard interception return touchdown and Vandyke’s second punt block, which was recovered by Burks in the end zone, sealed the outcome.

They were the eighth and ninth return touchdowns of the season for the Stallions.

Lifting the championship trophy wasn’t the end of the day for Vandyke, though.

“Now I’m going to go home,” he said. “And then go back to work.”