BOSTON (AP) — Franchy Cordero hit a grand slam with two outs in the bottom of the 10th inning, lifting the surging Boston Red Sox to an 8-4 victory over the Seattle Mariners on Sunday. Trevor Story continued his recent power surge with his fifth homer over the Green Monster in four days and Christian Arroyo added a solo shot for Boston, which posted its season-high fifth straight victory and completed a four-game sweep over Seattle. The Red Sox trailed 4-3 when pinch-hitter Christian Vázquez singled against Andrés Muñoz (1-2) in the 10th, advancing automatic runner Bobby Dalbec.