The third quarters played paramount roles yesterday in two opening-round games of the IAABO Girls Christmas Classic at Prince George's Community College.

No. 7 Springbrook was a 63-45 winner over No. 12 Mount Hebron, and Western of Baltimore defeated No. 13 DuVal, 62-42. Each game was decided by third-quarter flurries.

Springbrook and Western, the defending Baltimore city champion that extended its winning streak to 33 games, will meet tonight at 6 in a semifinal game. Mount Hebron will face DuVal at 2 in a consolation.

In other opening-round games last night, Lee defeated Northern, 70-52, and Largo edged Seton, 48-45. The winners will play tonight at 8, the losers at 4.

Springbrook (5-0), with just three seniors, is certain to receive a boost of confidence from its defeat of Mount Hebron (4-2), the defending Maryland Class 2A champion.

And it appears that the third quarter has become the Blue Devils' specialty. A week ago, Springbrook took control of a game when it held Quince Orchard to two points during that period.

Springbrook nearly duplicated its feat against Mount Hebron. It limited the Vikings to two points for the first 5:47 of the quarter and six for the period. Meanwhile, the Blue Devils scored 14 points to transform a 32-26 halftime edge into a 46-34 margin entering the fourth.

"We went to a zone to shut them down in the third quarter," said Springbrook Coach Bill Wiley. "We were able to stay with it defensively and they had more problems with that than the man-to-man. Also Mount Hebron went a little bit cold and we didn't allow them to get back in the game."

Led by 6-foot junior Cecilee Campbell (game-high 19 points and 11 rebounds) and 6-foot sophomore Lora Aggour (12, 13), the Springbrook frontcourt contributed 39 points and 27 rebounds.

Guards Christy McCauley (13 points) and Cescili Drake (nine points) were the Vikings' top scorers, with the majority of their shots coming from the outside.

"We had the size advantage and I think we used it well," said Wiley.

Though she was limited to three-for-13 shooting by Mount Hebron's man-to-man defense, Springbrook junior guard Cindy Weisman (11 points) teamed with backcourt mate Tanya Wolfram to provide steady ballhandling that let the Blue Devils deal with full-court pressure.

"Mount Hebron is known for its tenacious press," said Wiley. "But I thought we handled it pretty well. Our ballhandling was better than it has been all season. I think that was the biggest factor."

DuVal (3-2) trailed by 26-23 at halftime.