The Mets have turned this year’s edition of the Subway Series into their own two-borough party, especially after socking it to the Yankees again Wednesday night with a 9-4 victory at the Stadium. It is their third straight win in this year's battle between the teams, clinching the season series, and Met fans got into the act early, starting “Let’s Go, Mets!” chants in the Bronx as their offense pummeled Yankee pitching and Jeremy Hefner did enough to finally earn his first victory of the season. And two Mets in danger of being demoted, Ike Davis and Ruben Tejada, contributed, too, which perhaps complicates the Mets’ decision-making process on both struggling players. Tejada led off a five-run first inning with a single off loser David Phelps, and Davis drilled a two-run single in the first to KO Phelps and added another hit in the fifth inning. It all added up to the Mets taking the Subway Series for the first time since 2008 with one game remaining Thursday night at the Stadium. The Mets are now 3-8-6 in all-time Subway Series. They also have their first four-game winning streak this season, while the Yankees are mired in their first four-game losing skid. Yankee fans in the announced crowd of 43,681 began heading for the exits in the later innings. Tejada came out of the game in the ninth inning after he apparently hurt himself pursuing a foul ball. He fielded a grounder on the very next play, but the Mets’ athletic trainer came out to examine him after he threw to first. He was replaced at short by Justin Turner. Hefner (1-5) allowed three runs and nine hits in six innings, thriving while pitching with a big lead, an unusual experience for him this season. Until Wednesday night, the Mets had been 0-9 in his starts and 0-10 the day after their ace, Matt Harvey, pitches. Phelps (3-3) seemingly had bloomed into a dependable starter for the Yankees, but he was booed off the mound after getting only one out in the first inning.