Up five at halftime, the Blue Devils (10-1) were able to create more breathing room with a 21-13 edge in the third quarter.
Raynere Thornton led Marietta with 15 points and eight rebounds. Tyrell Tomlin added 12 points and D.J. Bostick 10.
Marietta will play in the tournament semifinal today against the winner of a first-round game between Marist and Hapeville Charter.
Shiloh Hills Christian 73, Mountain Area Christian 48: The Challengers led 26-10 at the end of the first quarter and 51-21 at halftime, en route to the Georgia Christian Athletic Association road victory.
Mac Jones was 12-of-18 from the field and finished with a team-high 24 points. Jon Allen had 18 points, eight rebounds and seven assists, while Trey Bleck contributed nine points.
Shiloh Hills (13-4, 4-0) shot better than 60 percent from the floor and almost 60 percent from 3-point range.
Kell sweeps tri-match: The Longhorns cruised to a pair of lopsided wins, beating Campbell (57-18) and Hiram (42-18).
Six Kell wrestlers — Matthew Springfield (120 pounds), Alec Prokop (132/138), Brian Link (132/138), Cody Ashway (145), Sam Ashway (152), Devin Baker (170) — finished with a pair of wins on the night, with all but Baker recording a pin. Baker’s two wins came via forfeit.
It its match with the Longhorns, Campbell got wins from Joneisha Sams (113), Bernard Robinson (126) and Dekevion Byrd (285). Byrd’s came through a pin.