Keaton Winn pitched four-hit ball over six-plus innings, Michael Conforto homered against his former team and the San Francisco Giants opened a three-game home series against the New York Mets with a 5-2 victory on Monday.Nick Ahmed and Matt Chapman contributed two-run hits, helping the Giants respond to a loss with a win for the sixth consecutive time.Pete Alonso hit his seventh home run of the season in the fifth inning to account for the New York scoring until a Camilo Doval wild pitch allowed Brandon Nimmo to score in the ninth.Winn (2-3), who lost his first three starts of the season, posted nearly identical stats against the Mets to those he compiled in a 3-1 win over the Marlins on Wednesday. At Miami, he went six innings, allowing four hits and one run with one walk and four strikeouts.This time around, Winn got into the seventh inning, though he didn’t retire a batter in that frame, while giving up four hits and one run with one walk. He struck out six, tying his season high.The Giants gave the young right-hander all the runs he would need in a two-run second that was set up by singles from Jorge Soler and Conforto. With two outs and the bases loaded, Ahmed singled on a ball that never left the infield, sending both Soler and Conforto home.Chapman’s big hit — a double — made it 4-0 in the third after Wilmer Flores walked and Jung Hoo Lee singled.After Alonso’s homer narrowed the New York deficit to 4-1 in the fifth, Conforto, who hit 132 homers in seven seasons for the Mets, got that run back with his fifth homer of the season leading off the sixth.