The Mets, who have won two in a row after dropping six straight, scored four of their first five runs on homers before taking a two-run lead off Walden (1-1) in the 10th.
In the 10th, pinch-hitter Jordany Valdespin drew a two-out walk from Walden and stole second base when closer Bobby Parnell squared around to bunt while taking a strike on the first pitch he saw.