Pete Alonso had two home runs and five RBIs to help the New York Mets extend their winning streak to four games with a 12-6 victory against the visiting New York Yankees on Saturday.Mets starting pitcher Frankie Montas (1-1) allowed four runs on five hits in 5 2/3 innings.Starter Carlos Rodon (9-6) gave up seven runs (six earned) on five hits over five innings for the Yankees, who have lost a season-high six straight.Already leading by three in the fifth, the Mets built upon it after Francisco Lindor drew a walk and set the stage for Alonso’s 19th home run of the season to go ahead 7-2.The Yankees narrowed it to 7-4 in the top of the sixth. Oswald Peraza and Trent Grisham each singled and advanced on an Aaron Judge groundout. Cody Bellinger then brought both runners home with a double.Anthony Volpe added another run in the seventh when he launched a fastball into the seats in left-center field.The Mets added insurance in the home half of the seventh as Lindor drove in Ronny Mauricio with a single against reliever Scott Effross to make it 8-5. Then, with Lindor and Juan Soto on, Alonso belted another homer, off Jayvien Sandridge in his major-league debut, to extend it to 11-5.Ben Rice drove in Bellinger in the eighth to make it 11-6, but the Mets pushed it to 12-6 in the bottom half when Lindor scored on a Soto base hit.