A double reverse toss back to quarterback Cable netted the Goats a 44-yard touchdown, with Dalton Longenbaugh being on the receiving end to put the Goats up 13-0 with 11:08 to play in the third.
The Goats continued to remain in full control of things and expanded their lead to 27-0 with 7:37 to play in the game.
Rusk finally got on the scoreboard with 4:28 showing on the clock when Glenn plowed in from a yard out.
Chris Sanchez tacked on the extra point, which cut the Goat lead to 27-7.
Glenn's touchdown was the first points that the Eagles have scored in district play this season.
Glenn, Isiah Francis and Drew Dorsey led the Rusk ground attack, with Sanchez reeling several nice mid-range passes from quarterback Bryan Paddock.
Defensive leaders for the Eagles were Sean Bixler, Josh Ruiz, Austin Ballew, Jeremy Turner and Taylon Sturns.
Rusk 0 0 0 7 — 7
Groesbeck 7 0 13 14 — 34
G-Cody Favors 46 pass from Sterling Cable (Stephen Featherson kick), 9:25
G-Dalton Longenbaugh 44 pass from Cable (pass failed), 11:08
G-Cable 1 run (Fernando Lique kick), 2:13
G-Jaylon Medlock 31 pass from Cable (Lique kick), 7:37
R-DJ Glenn 1 run (Chris Sanchez kick), 4:28
G-Devin Kozak 2 run (Lique kick), 1:45