BOSTON — The toughest moment of Mike Leake’s stellar night was missing a chance for a shutout. Leake pitched eight sparkling innings, Mitch Haniger drove in three runs and the Seattle Mariners snapped a season-high five-game losing streak with a 7-2 victory over the Boston Red Sox on Saturday. With closer Edwin Diaz needing some work, Seattle manager Scott Servais had to deliver the bad news to Leake. “Very tough, very, very hard,” Servais said.