LYNN – There’s an old baseball saying that when there’s a good pitcher on the mound, you’d better get to him early. Because if you let him off the ropes, that’ll be your last chance.The St. Mary’s girls hockey team was the good pitcher last night. And Reading had an excellent chance to score an early KO. The Rockets certainly had the Spartans on the ropes, scoring only 30 seconds into the game to stun both the players and the fans.But just like Josh Beckett or Johan Santana, the Spartans found their groove, and settled in for the rest of the game.The result was a 4-1 win to move their record to 20-0, with one game remaining on Thursday against Boston Latin. If they win, they’ll have had the greatest single regular season in school history (the baseball team went 20-0 two years in a row in the late 1980s, but this team will have won one more).The Rockets, who are coached by former US Olympic gold medal winner and Saugus native Sandra (Whyte) Sweeney, put a scare into the Spartans right off the bat as Dominique Lozzi and Amanda Delaney skated in on goalie Kelsey Magrane practically off the faceoff, with Lozzi slapping it home at the 0:30 mark.”I could tell just from warmups that we were flat,” said coach Frank Pagliuca. “It’s the first time all year, really.”And even after that, I don’t think we really played our game until the third period,” he said. “That last 15 minutes, we played our kind of hockey.”By then, the outcome was already beyond doubt and the Spartans put on a forechecking clinic that kept the action in the Reading end for practically the entire 15 minutes.St. Mary’s tied the game at the 7:36 mark of the first period simply by storming the Reading net. Abby Gauthier scored the first of her two goals, and Courtney Winters got the first of her three assists, when Team Spartan just descended en masse on the Reading net.St. Mary’s got the tiebreaker at the 5:26 mark of the second period on the power play. Alex Smith shot one from the point that made its way through a screen into the Reading net, and it was 2-1. Before anyone could look up from that goal, Gauthier, with Christen Hart and Winters assisting, made it 3-1, eight seconds later.By now, St. Mary’s was really picking up steam, and the Spartans got goal No. 4 with 3:55 left in the second period, with Caitlin Gottwald shooting a soft shot through another screen.The win could be costly, however. In the second period, McAndrews, who is also a catcher on the softball team, went hard into the boards and came away with a shoulder injury. She went to the hospital for X-rays as soon as the game ended.Gauthier, also, took a hit to the ribs in the second period, but she stayed in the game and didn’t miss a shift.