On a night when the Baltimore Orioles had all sorts of problems with runners on base, Chris Davis finally delivered the pivotal hit. It wasn't a thing of beauty, especially from the major league leader in home runs. Not that the Orioles cared. Davis singled home the tiebreaking run with two outs in the 13th inning, giving Baltimore an exhausting 5-4 victory over the Boston Red Sox on Thursday night in the opener of a four-game series between AL East contenders.