The Hatters will play at sixth-seeded Downingtown West in the quarterfinals Friday.
It took Hatboro-Horsham (13-5-1) 10 minutes to sustain a possession. With a little less than 15 minutes remaining in the first half, a misguided pass from a Colonials defender found the stick of Hatters midfielder Casey Swezey. Swezey drove toward the net and passed to Eldridge, who scored.
"We knew we had to get the first goal to get the other team shaking," Eldridge said.
The Hatters kept Plymouth Whitemarsh (17-2) on its heels for the remainder of the half. With a little less than nine minutes to play, Eldridge found sophomore Syd Rausa off a penalty corner to push the lead to 2-0.
Less than a minute before the break, PW earned three consecutive penalty corners, but failed to capitalize.
"It was really tough," Colonials coach Marianne Paparone said. "The first 10 minutes we dominated, but once we gave up that goal, the momentum shift was there. At the end of the half, we definitely put pressure on them, and to not put one in was tough."
The Colonials couldn't get a threatening shot on Hatters goalkeeper Emily Braunewell in the second half. Braunewell was forced to make just four saves for her shutout.
"It wasn't so much that we expected to shut them out," Braunewell said. "But I think we had the thought process that we were going to come in here and win."
Hatboro-Horsham 2 0 – 2
Plymouth Whitemarsh 0 0 – 0
Goals: HH-Colby Eldridge, Syd Rausa.
Saves: HH-Emily Braunewell 4; PW-Tori Byrne 8.