He did, although 3 players younger than Zaha (although not as young as JFC) have subsequently scored at the Amex: Sean Murray for Watford, Nathan Redmond for Birmingham and Ademola Lookman for Charlton.
Prior to today, Emile Heskey was the oldest scorer at the Amex (scored for Bolton on February 13 2016). He was 7 days older than Kevin Phillips was when the Blackpool striker notched his brace.
However, Ashley Cole is 25 days older than Heskey was, so he now takes the accolade.