Throughout this season, these Washington Nationals have displayed a head-scratching inability to get runners home, often having a tough enough time simply getting them on base. For at least one inning on an unusually chilly May night, they exorcised their situational hitting demons. Scuffling bench players came to life. Runners weren’t stranded on base. Against division rival Philadelphia at Nationals Park on Friday, the Nationals’ offense finally found its footing in a four-run fifth inning, their highest single-inning output in a month. The explosion propelled Washington to a 5-2 victory. The Nationals not only put runners on against Phillies right-handed starter Kyle Kendrick, they also drove them in. Their offensive efforts supported a strong outing by Jordan Zimmermann, who battled a stiff neck on a cold night to become the first National League pitcher to reach eight wins. The Nationals’ fifth inning started, predictably, with a single from Bryce Harper. Adam LaRoche followed with a triple to deep center, a hit aided by the misplay of center fielder Ben Revere. Two batters later, Kurt Suzuki singled home LaRoche. And after an infield single by struggling Tyler Moore snapped a 0-for-23 slump and put a second runner on base with two outs, Steve Lombardozzi, starting for the injured Danny Espinosa, drilled a two-run double to right. “Just kind of keeping the line moving, that’s the biggest thing,” said Lombardozzi, who learned on Friday he will see more time at second base while Espinosa rests a fractured right wrist he has played with for a month. “Not trying to hit a five-run homer, just moving the line.” The Nationals’ offense looked like the run-producing lineup many expected to see from start of the season. The Nationals entered Friday’s game hitting .234 with runners on base, the third-worst mark in the major leagues. The Nationals had four hits with men on in the fifth inning alone, chasing Kendrick, who entered with a 2.82 ERA. “We haven’t seen much of that all year,” said Manager Davey Johnson, who had vowed before the game to not shave the facial hair on his chin until the offense came to life.