Despite entering their first-ever continental adventure, Oliver Glasner's side are adapting at a rapid pace. Without key players like striker Jean-Philippe Mateta and wing-back Daniel Muñoz, the London club left Dublin with a commanding result that virtually guarantees them a place in the Europa Conference League qualifying rounds.
Another three points in their upcoming fixture against Finnish KuPS ought to be enough to seal direct passage to the last 16, particularly after a previous stumble against Strasbourg.
This occasion offered a chance for some of Palace's lesser-used talent to shine. Christantus Uche, making only his second beginning since arriving on loan from Getafe, opened the scoring with a clinical goal. Forward Eddie Nketiah added a another, scoring for the second game in match.
A Shelbourne team that had finished their league season were no match even for a mostly rotated Palace outfit. The visitors were further depleted by the news that Mateta and Muñoz are sidelined with knee injuries.
Despite heavy rain in Dublin, Palace rapidly established dominance. A flowing move in the 11th minute, initiated by Daichi Kamada's clever pass, let Nketiah to set up Uche for a straightforward tap-in.
Youngster Adam Wharton came close minutes later, fizzing a long-range shot over the bar. Nketiah then claimed for a penalty after bursting into the area, but the referee waved away the appeals.
Ex-Arsenal man did not have wait long to get his goal, tapping home from close range after Uche's shot had struck the post.
The home side were clinging on desperately. Full-back Kameron Ledwidge was lucky to escape a booking for two agricultural tackles on Yeremy Pino, before Chris Richards rattled the crossbar with a powerful header from a corner.
The contest was effectively over eight minutes from half-time. Yeremy Pino weaved past a series of weak challenges before coolly slotting a shot past keeper Wessel Speel to extend the lead to 3-0.
After the break, coach Oliver Glasner seized the opportunity to withdraw key individuals like Kamada and Wharton. Replacement Romain Esse almost scoring with his first touch, only to see his effort blocked.
Esse was desperately unlucky later on, seeing one attempt crash off each posts before being gathered on the line. Uche then blazed a glaring chance, indicating there is still scope for development in his game.
A solitary worry for Palace was a late injury to Justin Devenny, who was forced off. This allowed 17-year-old forward Benji Casey to make his first-team debut, capping an otherwise perfect night for the visiting side.