Luis Severino and three relievers combined on a five-hitter Wednesday afternoon for the host New York Mets, who beat the Pittsburgh Pirates 9-1 to complete a three-game sweep.Starling Marte and Harrison Bader both hit two-run homers while Tyrone Taylor and Brandon Nimmo each had two-run singles for the Mets, who have won 10 of 13. Francisco Alvarez had an RBI fielder’s choice in the eighth. Taylor finished with three hits.Bryan Reynolds delivered a run-scoring infield single for the Pirates, who have lost six of eight. Oneil Cruz had a pair of singles.Severino (2-1) gave up an unearned run on five hits and three walks while striking out four over a season-high six innings. Jorge Lopez, Jake Diekman and Grant Hartwig tossed a perfect inning apiece.Pirates starter Bailey Falter (1-1) allowed two runs on four hits and one walk while striking out four over five innings.The Pirates took a brief lead in unusual fashion in the third.