Senior Trisha Mockapetris recorded her 200th kill of the season in the win, and sophomore Meghan Kelley also helped lead the offense.
The Eagles will attempt to win their 15th state title, starting with the state semifinals at the University of Maryland's Ritchie Coliseum on Wednesday.
No. 1 Arundel d. No. 6 Severna Park, 3-1: The host Wildcats (18-0) won every set, except the third, over the Falcons (14-4) in Class 4A East regional finals.
"All season, we lost three out of four matches to Arundel," Severna Park coach Tim Dunbar said. "We were flat, and they [Arundel] were consistently tough."
Sophie Hoekstra had 18 digs and 11 kills, and Kara Glynn had 14 kills for Severna Park.
No. 5 Bel Air d. Towson, 3-0: Celeste Roland had 15 kills and eight digs, Tia Williams had 12 kills and two aces, and Amanda Rodriguez added 30 assists and two aces to power the host Braves (19-0) over the Generals in the 3A North regional final. The scores were 25-10, 25-17 and 26-24.
Calvert d. No. 9 Glenelg, 3-1: The visiting Gladiators (13-4) came back to win the first set but lost the next three to the undefeated Cavaliers in Class 2A South. Calvert won at the service line and at the net.
No. 9 Fallston 1, Calvert 0: The Cougars (15-2-2) scored with just three seconds on the clock Friday night, to beat Calvert, 1-0, in a Class 2A state semifinal played at Bel Air.
Cougars' sophomore Logan Gasior followed up her own corner kick and hit a shot on goal from the right side. The ball struck squarely off the inside of the far post and bounced back along the goal line, before bouncing off a Calvert defender and back into the net.
Cougars goalie Kayla Reilly finished with four saves.
--Randall L. McRoberts
Baltimore Sun staff contributed to this article.