BOSTON — Sandy Leon was frustrated he didn’t drive one run in with a safety squeeze. Instead, he drove in three with a drive over the Green Monster. Leon fouled off his bunt attempt, then hit a three-run homer to cap an eight-run third inning that carried the surging Boston Red Sox over the struggling Seattle Mariners 9-5 on Saturday. “If he gets it down, we score a run and have a runner at second,” Red Sox manager Alex Cora said.