Francisco Alvarez homered in the second inning and laced a key two-run double in the seventh on Saturday for the host New York Mets, who beat the Philadelphia Phillies 6-3 in the third game of a four-game series.The win by the Mets (86-69) prevented the playoff-bound Phillies (92-63) from clinching their first National League East title since 2011. Philadelphia’s magic number stayed at one heading into Sunday’s series finale.New York entered Saturday holding the third NL wild-card spot, a game behind the Arizona Diamondbacks and two games ahead of the Atlanta Braves.Kyle Schwarber homered leading off the game against Mets starter Sean Manaea (12-5) before Alvarez and Luisangel Acuna went deep in a three-batter span in the second against Phillies starter Ranger Suarez. Acuna is the third player in team history with at least three homers in his first seven big-league games in which he has had at least one plate appearance.Nick Castellanos homered in the fifth for Philadelphia, and the Mets stranded five runners between the third and sixth before breaking through against Orion Kerkering (5-3) in the seventh. Starling Marte drew a leadoff walk and Pete Alonso was plunked one out later before Brandon Nimmo blooped an RBI single to left-center field to put New York up 3-2.After Tyrone Taylor struck out, Alvarez doubled just past a diving Weston Wilson in left field to plate two more runs.