Mother Nature was the star of Sunday’s series finale. Clay Buchholz was a close second. Buchholz didn’t show any ill effects of the AC joint issue that forced him to skip a start, and he was dominant before downpours ended the game prematurely in the sixth inning. The right-hander tossed five shutout innings to help give the Red Sox a 3-0, rain-shortened victory. Buchholz’s short, but sweet outing put the finishing touches on what was an overall gritty weekend for the Red Sox. Boston started the series off on the wrong foot by failing to generate any offense against CC Sabathia and Co. on Friday, but the last two games — or one game and change, to be exact — went a long way toward showing that the Red Sox are still the class of the American League East. It wasn’t just about the end result on Saturday and Sunday, although two wins are two wins, no matter how you slice it. It was the manner in which the Sox emerged victorious. Friday was a deflating day for the Red Sox. The news of Jacoby Ellsbury’s injury coupled with Jon Lester’s third straight subpar outing and Boston’s anemic offense made for a major letdown after the Red Sox blew the doors off the Phillies in Philadelphia on Thursday. The club needed a pick-me-up, and Saturday’s offensive outburst provided just that. The Red Sox scored 11 runs and banged out 18 hits en route to a convincing victory against Phil Hughes and the Yankees. The Sox received contributions from all over, and even Felix Doubront, who went six strong innings, was a bright spot. Pitching wasn’t necessarily the name of the game for Boston on Saturday, though, as it was the offense that stole the show. On Sunday, however, Buchholz’s outing, albeit short, was impossible to overlook. The right-hander issued a one-out walk to Robinson Cano in the first inning, but he pounded the strike zone for the rest of the evening. Following the free pass to Cano, Buchholz didn’t go to any three-ball counts and he was in complete control, allowing just two singles the rest of the way. His fastball was excellent, his cutter was nearly unhittable and his offspeed stuff kept the Yankees’ hitters on edge.