Williamsville South left its rivals feeling a little trapped on Sunday.

The Billies won their first Section VI girls basketball title with a 37-35 win over Williamsville East in the Class A-1 final at Buffalo State Sunday.

After East put up 22 points in the first quarter, the Billies switched defenses. They went to a suffocating half-court trap resulting in East scoring just 13 points over the final three quarters, none in the fourth quarter.

“We really like this trap, we think we have the right personnel for it,” said South coach Kristen Dolan. “We were playing a different defense in the beginning of the game, and it wasn’t working. Then we said you know what, ‘we’ve got to go back to what’s worked all season and what’s made us successful.’ ”

South was led by guard Emily Smith with 15 points, but it was senior Morgan Maley who delivered six huge points in the fourth quarter. Her runner with 3:06 left gave the Billies the lead for good at 36-35.

South (15-5) will play East Aurora (18-3) for the overall Class A title on Wednesday at 6:30 p.m. at Buffalo State. The Blue Devils eliminated Maryvale, 48-38, to win the Class A-2 crown.

East was led by promising eighth-grader Erica Martinsen with 10 points. The Flames were also slowed by 4-of-12 shooting from the free-throw line and 17 turnovers.

Meanwhile, East Aurora put the finishing touches on its first Section VI title since winning back-to-back Class B-1 crowns in 2006 and 2007.

The win was the third of the season for East Aurora over Maryvale. The Blue Devils rode a solid start and led by as much as 31-13 early in the third only to see their lead slowly evaporate. Clutch free throw shooting in the last 1:12 helped hold off the Flyers.

East Aurora has reached the crossover final starting an eighth grader at center (Emma Brinker) and a freshman point guard (Julianna Meisenheimer).

Erin Nason led the scoring with 10 points for EA. Meisenheimer added eight points and had five assists. The Blue Devils held Maryvale to 13 points in the first half.

The game was the last in the high school career of Maryvale’s Ciara Rosten, who has signed with Massachusetts of the Atlantic 10. She led all scorers with 26 points, including 6 of 8 from the line. She finished her career with 1,574 points.

EA defended Rosten in a variety of ways picking her up full court, using a box-and-one, using someone tall, someone quick.

“We tried to mix up who played her, tried to keep someone fresh on her,” said EA coach Gary Schutrum. “We wanted to force other girls from the Maryvale squad to do things.”