"The little run they put together to end the first half was the difference in the game," Williamsport coach Deron Crawford said.
"The second half coming out may have been more important than the nine points to close the first half," Hubs coach Tim McNamee said.
The Wildcats (9-8, 6-7) had no answers for for North's hot shooting. The Hubs shot only 36 percent against South, but made 28 of 46 shots (61 percent) against Williamsport - which played without leading scorer Nick Adenhart, who is out indefinitely with mononucleosis.
"Nick's a great offensive player, and I don't want anyone to feel sorry for us, it's just a bad break right now," Crawford said. "(North) shot the ball so well tonight. You have to try to take away something. We tried to take away the inside game, and Gantt came in and shot the ball so well."
Gantt checked in to start the second quarter and nailed a 3-pointer and a 16-foot jumper to give the Hubs a 23-12 lead. He'd add two more jumpers, including one with 15 seconds left in the half that closed North's first run.
"He gets the game ball tonight, and that's a good sign," McNamee said of Gantt, who had 16 points against South. "The last two nights, he's shot the ball better."
Spruce took control in the third quarter, making a floater down the lane and a 3-pointer from the left wing for the first five points of the 7-0 run. The final two came on Brian Bell's putback on a play started by Spruce's aggressive long pass down the floor in transition.
"That's where we got them," Spruce said of the two runs. "The key against Williamsport is you have to be up on them, because they run their offense to perfection, and they will hold the ball all day and make you chase them. So you have to get up on them or they will kill you."
Bernard Harris had 12 points and Marshall Branch had 10 points and 10 rebounds for the Hubs.
Josh Foley led Williamsport with 16 points, while Ben Jordan had 13 and Will Roney and Dustin Bachtell each had 11.
No. 5 N. Hagerstown 70, Williamsport 52
Foley 16, Jordan 13, Roney 11, Bachtell 11, O'Haver 1. Totals 19 11-16 52.
NORTH HAGERSTOWN (70)
Branch 10, Harris 12, Spruce 11, Bellon 8, Claybon 8, Gantt 17, Brian Bell 2, Hose 2. Totals 28 9-14 70.
Williamsport 12 11 9 20 - 52
N. Hagerstown 18 18 12 22 - 70
Three-point goals - Williamsport 3 (Foley, Jordan, Bachtell), North 5 (Harris, Spruce 3, Gantt).