Rashard Odomes scored 23 points and Killeen hit only one field goal in the final four minutes as Cove pulled away 80-68.
Odomes scores nine points in the third as Cove leads 56-52 after three.
The Roos offense comes alive as Brian Long has 12 points and Killeen leads 41-34 at the half. Elijah Sobers has 13 for Cove at the break.
The Roos close out the first on a 14-4 run. Long has six points for Killeen while Sobers has nine for Cove.
Dawgs lead 20-19 after a quarter.
The winner of this tiebreaker gets the third seed and Duncanville in the Region I-5A playoffs. The loser finishes fourth and plays Desoto.