Sierra of Manteca dominated the second half and took first place away from Sonora High School with a 53-39 girls' basketball victory last night at Bud Castle Gym.

The Timberwolves (18-6, 9-1) lead the Wildcats (14-7, 8-1) by a half-game and are poised to at least share their first Valley Oak League championship.

Center Martha Spivey scored 23 points to lead Sierra, which outscored Sonora 35-19 after halftime to snap the Wildcats' eight-game winning streak and avenge a 45-41 loss to them Jan. 21 in Manteca.

The victory was, without question, the biggest in Sierra's eight-year history.

"The girls worked hard for this and they played hard tonight," Sierra coach Dan Cunial said after the game. "We did a good job of taking away their best player."

That would be Sonora center Jessica Peterson, who had 13 points and 15 rebounds but was unable to get the ball consistently in scoring position against the physical defensive play of Laura Crawford and Tracee Smith.

Also, Sonora couldn't get hot from the perimeter, committed a number of key turnovers, and was unable to come up with key defensive stops. It was the latter that most bothered Sonora coach Charmon Logan.

"I was really disappointed with our defense," Logan said, noting that Sierra scored more points in a half than the Wildcats had been giving up per game (33) in VOL action. "(Sierra) came ready to play."

While Spivey did most of the Timberwolves' scoring, the player who controlled the flow of the game was Sierra guard Davina Ruiz, who bedeviled Sonora with seven points, six rebounds, and nine assists.

Ruiz assisted on all five field goals in a 12-0 run with which Sierra took control early in the third quarter, turning a 23-18 deficit into a 30-23 lead. Sonora never got closer than six points the rest of the way.