BILLERICA – There was a point this season that the Marblehead High hockey team had to think its chances of qualifying for the state tournament let alone going anywhere fell dangerously close to the slim to none category.The Headers were 1-4 in their first five games and around the midway point, they sported a not so stellar 3-8 record. Fast-forward a few weeks and this year’s Cinderella team is heading to the Division 3 state semifinals after defeating Concord-Carlisle, 1-0, in the North final at Billerica.Marblehead will play the winner of Scituate/Westwood next Thursday at the DCU Center in Worcester (6). The winner of that game will play for the Division 3 state title at the Boston Garden.”The guys did a tremendous job,” Marblehead coach Bob Jackson said. “They reached down deep.”Jackson said the tough schedule his team faces in the Northeastern Conference, with Division 2 tournament teams like Peabody, Danvers and Gloucester, served as good preparation for the tournament. The battle-tested Headers needed nerves of steel in all four tournament games, beginning with an overtime win over rival Swampscott, a shootout win against Latin Academy and a 1-0 win over Triton.”That’s kind of what we tell the kids. We need to play our game. We face tough foes on a regular basis,” Jackson said. .After scoreless first and second period, a sense of urgency set in for both teams in the third. It looked like Marblehead had finally found a chink in the Patriots armor when freshman forward Chris McLeod got off a slap shot from outside the blue line that found its way through Concord-Carlisle keeper Jon Nessa’s pads and slid to the goal line. A Concord-Carlisle player swooped in and swatted the puck out of the crease just as it was about to go over the line. The Marblehead coaches argued that it had gone in, but to no avail.The controversial call loomed large until four minutes later, when Chris Donahue let go a slap shot from the point that Andrew Bates tipped in for the game-winner. Anders Gundersen also picked up an assist on the play.The final 8 1/2 minutes were wild, with Marblehead goalie Aaron Reny turning into the rock of Gilbralter as the Patriots went into assault mode. Reny turned back three tough shots around the six-minute mark and there was a mad scramble in front of the Marblehead net with about a minute left, after the Patriots had pulled their goalie. Concord-Carlisle missed the net a couple of times on point-blank shots that went high, side and everywhere but where they were suppose to go.”It was a great feeling,” Reny said about being in net during that intense final few minutes, “but I was more happy that we won the game. Our defense did a great job. I was seeing every single shot squarely. Even though they’re young, they’re very talented group.”The Headers were without one of their top guns, senior forward Eric Fader, who injured his elbow against Latin Academy. Fader, whose are is in a sling, was able to dress for the game after having a special sling fashioned for him that allowed him to wear the jersey. He didn’t play, but was there for moral support.Jackson said one of the keys in the win was depth.”I think we have a little more depth than them. We’ve been able to go with four lines (the first two tournament games) and six defensemen,” Jackson said, adding that he has eight freshmen dress and with 1:14 left in a 1-0 game, he had four of them out on the ice.Jackson said one of the other reasons the team has done so well after getting off to such a shaky start is that the players bought into the system the coaches were selling.”These guys have done a great job of drinking the Koolaid, as (assistant) coach (Tom) Colby talks about, drinking the Koolaid and having everyone row in the same direction. I think the last four games, we’ve been doing that.”