The Cardinals led 27-17 at the half and used a 10-2 third-quarter spurt to pull away, leading by nearly 20 heading into the twilight of the game.
The Trojans were able to put together a strong fourth quarter, with East Surry losing focus and allowing their hosts to cut the lead back down to 10 points.
The Cardinals recovered however, hitting seven of 11 fourth quarter free throws to seal the victory.
East Surry had a strong night inside, with Hunter Diamont and Andrew Hunter leading the Cardinals with 11 points apiece and Patrick Marion adding 10.
Also for East, Spence Tuttle finished with five points and nine rebounds, while playing tough inside defense all night.
Alleghany big-man Julian McNeil led the Trojans with 16 points in the loss.
East Surry led the Trojans 27-17 at the half.
The Cardinals shut down Alleghany on its home court in the third quarter, outscoring the Trojans 10-2 en route to a convincing victory.
The Cardinals will have a tough week ahead of them, as they host undefeated conference leader Bishop McGuinness Tuesday, then travel to Northwest 1-A rival North Stokes Friday.
The win improves East Surry to 10-10 overall and 9-4 in conference play.
Alleghany drops to 4-17 overall and 4-10 in the conference.
EAST SURRY 54,
East Surry 18 9 10 17 — 54
Alleghany 7 10 2 16 — 35
East Surry — Hunter Diamont 11, Andrew Hunter 11, Patrick Marion 10, M. Covington 6, S. Tuttle 5, W. Tuttle 5, Martin 4, Banks 2
Alleghany — Julian McNeil 16, Thomas 7, Calhoun 4, Weaver 4, Ruppard 2, Miller 2