TAUNTON – Sometimes, it’s better to be lucky than to be anything else. Just ask St. Mary’s.In the top of the seventh inning, with Tatiana Doucette on third base and two out, Cassandra LaFauci hit a bullet that the Case shortstop couldn’t corral. It rolled away, LaFauci reached safely and Doucette came home with the deciding run in a 4-3 Division 3 state semifinal softball win.Click here for a photo gallery.Then, in the bottom of the inning, Case’s Kelsey Pacheco hit a smash that St. Mary’s third baseman Kaleigh Finigan knocked down. But the ball ricocheted right to Molly Doyle at shortstop. She threw to first, with Taylor Cash making a nice stretch, to get the second out of the inning.That, as much as anything, is the short-form story of St. Mary’s win Wednesday at Jack Tripp Memorial Field in Taunton. Two line drives. Two distinct results.It was, of course, more than that. It was the Spartans spotting the Cardinals a first-inning 3-1 lead thanks to some very shaky fielding. It was Doucette, known more for her hockey, coming up big by knocking in the tying run and scoring the game-winner. And it was eighth grader (well, not anymore, she says) Mia Nowicki pitching the final three innings and getting the side in order in the seventh.”She was lights-out,” said St. Mary’s coach Colleen Newbury. “She’s been all year.”The plan going in was to pitch Brooke L’Abbe for four innings and finish up with Nowicki.”And I thought Brooke pitched well,” said Newbury. “We just gave them some runs.”St. Mary’s took a 1-0 lead in the top of the first when Alison Butler, who led off with a single and went to third on Finigan’s base hit, scored on a double by Doyle.But the bottom of the first was a nightmare for the Spartans and the only good thing you can say is that it wasn’t worse. Leadoff hitter Jenna Santierre tripled, but was thrown out at the plate on an attempted sacrifice. But with two out, St. Mary’s made two errors and Case ended up with three runs.The Spartans got one of those runs back immediately in the top of the second in a curious sort of way. With the bases loaded, Finigan was hit by a pitch.L’Abbe had baserunners in every inning she pitched, but she got out of jams. In the second, the first two Case runners got on before she retired the next three hitters. An inning later, with two outs, Case put runners at first and second, but ran itself into the third out on a baserunner’s interference.In the next inning, Santierre got an infield hit and Finigan made a spectacular catch on a popup to short left, running away from the infield, to keep that from escalating.St. Mary’s got the equalizer in the top of the fifth when Doyle doubled, L’Abbe singled, and Doucette ripped a base hit to left.Nowicki came on in the fifth and retired the side in order, and then worked around a two-out double to Santierre to keep Case off the board.In the top of the seventh, with two out, Doucette hit a gap double between left and center, and, after Doucette took third on a wild pitch, LaFauci’s smash broke through the shortstop’s glove and the winning run scored.There were plenty of palpitating moments in the bottom of the seventh. Sara Carvalho hit a line drive to left that Butler misjudged for a brief moment, but she made the catch. Then came Pacheco’s ground ball. Nowicki got Katie Van Lingen to pop to the catcher Doucette to end it.”I knew we were in for a tough opponent,” said Newbury, whose 2011 team was beaten in the semifinals by Case. “They’d lost two straight state championship games and I’m sure they wanted another crack at it.”St. Mary’s will play Assabet Valley Saturday at Worcester State College (time to be announced) for the state championship. The Spartans went back-to-back in 2009 and 2010.Steve Krause can be reached at [email protected].