Potomac forward Dion Wiley caught the outlet pass and fired a shot in one motion.

The Wolverines’ leading scorer was a good 25 feet from the basket on the left wing, but with the Maryland 3A South region final still in the balance, Wiley didn’t think twice about shooting.

“I always shoot it from right there,” Wiley said. “I practice it before every game in warmups, so I knew I could make it from that far.”

Wiley’s long-range three swished through with about 5 minutes 20 seconds to play in the fourth quarter, giving 10th-ranked Potomac a four-point lead and finally starting to deflate a scrappy Thomas Stone team that had matched Potomac practically shot-for-shot.

Wiley scored 16 of his game-high 24 points in the second half to lead Potomac to a 76-70 win before a packed gym on Friday night in Oxon Hill. His three-pointer keyed a 10-0 run that helped the Wolverines pull away.

Potomac (21-3) advances to the state semifinals for the first time since 2006, and will face 3A East champion Reservoir at Comcast Center on Thursday at 5 p.m.

“It feels great to get there,” Wiley said.

Potomac had a definitive size advantage over Thomas Stone (17-8), but the Cougars shot well from the outside in the first half and did enough in the paint to offset the slashing games of Wiley and his teammates Randall Broddie (22 points) and Romone Saunders (11 points).

Stone guard Jourdan Lamberth scored 11 of his 14 points in the first half, and guards Michael Briscoe (team-high 18 points) and Tony Doublin (14 points) also contributed from the outside while forward Jasc Williams (11 points) and Malik Gross pitched in down low.

“We knew that they’re a good team, but we didn’t want to change much about what we wanted to do,” Thomas Stone Coach Dale Lamberth said. “We just played our ball, and what you saw was how we’ve been playing all year.”

Neither team led by more than five points at any point in the first three quarters, and the lead changed hands 16 times, including 10 times in the third quarter alone.

But Potomac tightened its defense in the fourth quarter and Thomas Stone started missing shots

The win sparked an emotional celebration for Potomac Coach Renard Johnson and his team, who cut down one of the nets after the game.

“This is a big night for our program,” Johnson said over the public address system after the game. “Even if we’ve got no nets, we’re still practicing tomorrow.”

RESERVOIR 59, ANNAPOLIS 51 : The 11-man rotation that Coach Michael Coughlan has deployed all season paid dividends for the Gators on Friday in Fulton, as they outlasted Annapolis in the Maryland 3A East region final, advancing to the school’s first state tournament.

Third-seeded Reservoir (19-6) used its deep bench to win its 10th straight game and avenge a loss to Annapolis (18-7) in last year’s 3A East semifinals.

The Gators trailed by three after the first quarter and dealt with some early foul trouble, but senior reserves Brandon Franklin and James Simms helped them take a 22-21 lead at the half. They extended that advantage to 39-31 by the end of the third quarter, as the starters came alive and the offense got going.

“Annapolis made a little run, but the kids didn’t panic and they knocked down free throws when they needed to,” Coughlan said. “This group has matured nicely over the last 15 games or so.”

Andrew Simon contributed to this report.