The Arlington Catholic girls basketball team showed just why it’s consistently one of the best teams in the state Monday in a 66-50 win over St. Mary’s at Arlington.The Spartans (5-3, 2-2) led 16-10 after one quarter and 23-17 late in the second quarter, but AC went on a 12-0 scoring spree heading into halftime to take the lead for good. Things didn’t start out much better after halftime with Arlington Catholic scoring another six unanswered points.”We were chasing them the rest of the way,” St. Mary’s coach Jeff Newhall said. “We came out with great energy and outplayed them for the first 12 minutes, but after that we had some breakdowns and got tired. They proved why they’re one of the best teams in the state.”Bria Tiro led the Spartans with 22 points. Tori Faieta added 12 and Alison McCarthy had 10 points. AC sharpshooter Kelsey Roberson led all scorers with 25 points. Former Winthrop High star Meredith Soper contributed 19 points.BOYS BASKETBALLTech 76, Shawsheen 54At Billerica, the Tigers (3-2, 2-0 Commonwealth Conference) had this one in the win column early on. Victor Smith had another big night, scoring 21 points. Howard Homan added 15 and Felix Rios hit double figures with 12. Josh Cheever also helped out with nine points.”We’re just playing good defense,” Tech coach Marvin Avery said. “The defense is right where we want it to be.”Tech plays Chelsea Thursday (4:45) at Tech in a makeup game.GYMNASTICSWinthrop 137.4, Marblehead 124.95At Winthrop, the Magicians (0-1) had strong performances from Cassie Noonan, who finished first in vaulting (8.9), and Alexis Lemieux, who took third on bars (8.3).