LaFayette (4-2) led 24-20 at halftime and 34-29 after three quarters, but won the final quarter, 17-9, to pull away.
"Tonight showed how much we have improved since the first game of the year," LaFayette head coach Matt Swanson said. "We gave up 73 points to (Sonoraville) last time and just about half of that tonight. It all goes back to our defense."
Brittany Stallings had 14 points to lead the charge. Ashley Eady added 12. Kelsey Byrd finished with nine, Emily White eight and Morgan Mefford seven in the victory.
Noelle Defoor led all scorers with 16 points for the Phoenix (5-3) who dropped their third straight contest.
LaFayette will play at Cedartown on Friday.
