LOWELL – The wins are not always going to be pretty.That was the message last night after the St. Mary’s girls hockey team overcame an inspired effort by Arlington to win its Division 1 state semifinal matchup, 3-2, at Tsongas Arena in Lowell.It was the Spartans’ 50th straight victory dating back to 2007. The team’s last defeat was in the D1 semifinal, in a shootout, to Austin Prep. Now, the Spartans get a chance to defend their 2008 title Saturday (5) at the Boston Garden against Woburn, which defeated Hingham in overtime in the early game at the Tsongas – also 3-2.”Not every win is going to be 4-0, or a blowout,” Spartan coach Frank Pagliuca said. “I thought we came out in the first period flat – and a lot of the credit has to go to (Arlington). Obviously, they learned a few things from the game we played against them earlier this season (a 6-0 Spartan win), and it showed.”The Spartans also had to rely on some of their role players for this one, and things really didn’t click all night for the usual scorers. Of the leading scorers on the team, only Erin McAndrews lit the lamp. The other goals came from Mikaela Donovan and Genevieve Benoit.”I wish we’d played better,” said Pagliuca. “But at the same time, it was a team win. And that’s important, too. It wasn’t happening for the top lines, so our third line bailed us out.”St. Mary’s had a wide edge in shots (17-7), but that really didn’t indicate how the game went. The Spy Ponders (17-3-2), the fifth seed coming into the tournament, played the same kind of defense basketball teams usually use. They packed it in down low. They didn’t let much of anything through, and many of the shots the Spartans did get were blocked on the way through before they got to goalie Kim Hayward. Add to that some apprehension on the part of the Spartans and you had the formula for a slow first period.”I think we were tentative,” admitted defenseman Alex Smith. “I think we just were afraid to make a mistake.”Then the mistake finally did happen ? but it wasn’t the Spartans who made it. It was Pagliuca. The referee whistled a delayed penalty, and Pagliuca thought it was on Arlington. But it was on the Spartans instead. But by the time anyone knew what was really going on, Pagliuca had already whistled goalie Kelsey Magrane to the bench so he could put a sixth skater out there.But when Arlington finally touched the puck, and started speeding down the ice on a 2-0-1, it was obvious something was wrong. Before Magrane could get back into the net, Rebecca O’Quinn slid a shot along the ice that wrapped itself just inside the far post, and it was 1-0.”My fault,” said Pagliuca. “I told her to come to the bench. That’s on me.”Thankfully for him, the game wasn’t on him. Donovan tied the score on a scramble in front of the net, with assists from Smith and Meaghan Spurling. And when Benoit scored off a nice feed from Angela Dandreo behind the net, the Spartans had a 2-1 lead heading into the third period.McAndrews looked to give the Spartans a commanding lead at 3-1 (especially now that the Spartans could go into full backchecking mode), sliding one along the ice that just eluded Hayward. It looked like the Spartans were on their way.But on this night, the Spy Ponders wouldn’t quit. A St. Mary’s penalty in the final minute gave Arlington a 6-on-4 advantage, and with 16 seconds left, O’Quinn got her second on a backhander that beat Magrane halfway up (officially the first goal she’s given up in the tournament, since she certainly couldn’t be faulted for the first one).St. Mary’s skated away the final 16 seconds and the win.