The 17-year-old tormented the Gills defence and crashed home a great second half goal to level the scores at 2-2.
David Perpetuini fired the visitors in front on 23 minutes before Danny Granville levelled two minutes after the break. Guy Ipoua headed Gillingham back in front midway through the second half but Routledge came to the home side's rescue with a deserved equaliser on 70 minutes.
The first half was best forgotten with Perpetuini providing the only opening, scoring at the far post after a Rod Wallace cross from the right.
The second half showed a big improvement from Palace and Granville's far-post header levelled the scores on 47 minutes. But against the run of play Ipoua gave the visitors the lead again on 66 minutes although Hayden Mullins got the last touch before the ball entered the net.
Palace waited just four minutes to level with Routledge hitting an absolute beauty from 20 yards following a corner from Danny Butterfield.
The Eagles stormed the Gillingham goal in the final 20 minutes but luck deserted them as a Tony Popovic header hit the crossbar and Tommy Black missed an absolute sitter.
Palace boss Trevor Francis said after the match: "The first half was unacceptable and was a real disappointment. Something had to be done at half time and a change of system helped certain players.
"The players applied a lot more enthusiasm and looked to be enjoying it. Wayne Routledge is a breath of fresh air the way he plays the game."