The Devilettes went up 12-8 eight minutes in before Beech rallied to go in front 23-19 by halftime and 37-27 through three periods as the Lady Buccaneers improved to 23-7.
Shiya Hoosier had 11 points and Mia Dean 10 for Beech.
Lindsey Freeman led Lebanon with 15 points while Allissa Mulaski tossed in 10, including two three-pointers; Maleigha Oldham a triple, Addie Grace Porter and Christaney Brookshire two each and Aaryn Grace Lester a free throw as the Devilettes dropped to 20-11 for the season.
Lebanon will travel to the District 10-AAA champion - either Henry County or Rossview - at 7 p.m. Friday to tip off the Region 5-AAA tournament. Beech will visit the runner-up.
“Just got to bounce back on Friday,” Lebanon coach Cory Barrett said. “We’re going to play a good basketball team. We’ve got a good basketball team. Definitely a winnable game, whoever we play.”