Starting its season on a positive note, the Swampscott High baseball team defeated Melrose 5-1 in its season opener at Swampscott on Saturday.”Defensively, we made all the plays we needed to make,” Swampscott coach T.J. Baril said.Right-hander Sean O’Brien got the complete-game win for the Big Blue, going seven innings and allowing two hits and one walk while striking out eight and not allowing an earned run.”He was very efficient,” Baril said. “He was around the strike zone all day.”First baseman Nick Meninno led the offense with a 2-for-3 day at the plate, scoring two runs and hitting a solo home run.Swampscott has played Melrose the last three or four years, Baril said.BOYS LACROSSESt. Mary’s 11, Saugus 4At Manning Field, Tim Aylward led St. Mary’s with five goals. Chris Coito added two, and Tom Braswell, Stephen Poliskey, Mike Crawford and Frank Moreschi each had one. Kyle Torigian made 18 saves. St. Mary’s (1-2) won its first game of the season.Rich Tenorio can be reached at [email protected].