Mike Piazza homered Saturday night in his first at-bat after the New York Mets activated him from the disabled list. Piazza started against the St. Louis Cardinals in the catcher's first game since breaking a bone in his left hand Aug. 16. Piazza put the Mets ahead 1-0 in the second inning when homered off Jeff Suppan, his 15th home run off the season. ``I don't know what to expect. It feels good enough to go. Hopefully, at this point in the year I can help out a little bit,'' Piazza said before the game.