Only a mother could love the way the Red Sox have begun their defense of the World Series crown, struggling to find consistency at the plate and in the field, taking a step back with every step forward. What better time, then, than Mother’s Day to finally put it all together? It wasn’t only John Lackey delivering seven strong innings at a ballpark that, aside from its proximity to his Texas ranch, never has been among his favorites. And it was more than Dustin Pedroia looking again like the prototypical leadoff hitter that the Red Sox desperately need him to become. For a change — in fact, for the first time all season — the Sox scored in each of the first two innings yesterday, grabbing an early lead and never letting go en route to a 5-2 victory over the Rangers and their first series win at Texas since Aug. 22-25, 2011. Most importantly, though, the Sox won their third straight series and climbed above .500 (19-18) for the first time since April 3, when they were 2-1 after the opening series against the Orioles in Baltimore. “There’s just familiarity, as we get through 40 games now, with a number of the new guys that have come in from the offseason, integrating some young players,” manager John Farrell said. “There’s more of a known commodity in our clubhouse.” In other words, the Red Sox finally are finding their identity. And they look a lot like a team that will go as far as its starting pitching and the top of the order will take it. It’s no coincidence, for example, that the Sox won back-to-back games against the Rangers in which Jon Lester and Lackey each went seven innings, combined to allow only five runs and avoided major trouble by getting big outs like Lackey’s strikeout of Mitch Moreland with two on, two out and a three-run lead in the fourth. Since May 2, the Sox have won six of the last eight games in large part because Lester, Lackey and fellow starters Felix Doubront, Jake Peavy and Clay Buchholz have combined for a 3.26 ERA. “These guys have settled in,” said catcher A.J. Pierzynski, whose two-run single keyed a three-run first inning against Rangers lefty Robbie Ross. “The weather’s warming up a little bit, guys kind of know where they’re at, what they’re working with, and you can see that each time these guys take the mound they get a little more confident. They believe they can go out there and do what they’re supposed to do.” But the starters still need run support, and with longtime leadoff man Jacoby Ellsbury having defected to the rival New York Yankees in the offseason and young players filling out the lower half of the lineup, the offense has struggled to achieve continuity, not to mention hits with runners in scoring position. Pedroia has helped with the former. In 15 games since taking over the leadoff spot, he is 19-for-63 (.302) with 11 walks and a .405 on-base percentage. Over the last two games, in particular, he has reached base seven times, including a leadoff double in the first inning against Ross and a solo homer in the seventh to stretch the lead to 5-1 and make life easier for Lackey.