Despite embarking on their first-ever continental campaign, Oliver Glasner's side are learning at a rapid pace. Missing star players like striker Jean-Philippe Mateta and wing-back Daniel Muñoz, the London club left Dublin with a commanding win that virtually secures them a place in the Conference League qualifying rounds.
Another victory in their upcoming fixture against Finland's KuPS should be enough to secure direct passage to the knockout stages, especially after a previous setback against Strasbourg.
This match offered a platform for several Palace's fringe talent to impress. Christantus Uche, in only his second beginning after joining on loan from Getafe, notched the account with a clinical goal. Forward Eddie Nketiah added a second, scoring for the second consecutive match.
The Shelbourne team that had concluded their domestic season were no match even for a mostly rotated Palace outfit. The visitors were further weakened by the news that Mateta and Muñoz are sidelined with knee problems.
Despite heavy rain in Dublin, Palace rapidly established dominance. A flowing passing sequence in the 11th minute, initiated by Daichi Kamada's clever pass, allowed Nketiah to set up Uche for a simple finish.
Youngster Adam Wharton came close minutes later, driving a long-range effort over the bar. Nketiah subsequently appealed for a penalty after racing into the box, but the referee waved away the appeals.
The formerArsenal man didn't need to wait long to get his goal, tapping home from a yard out after Uche's effort had hit the post.
Shelbourne were hanging on desperately. Defender Kameron Ledwidge was fortunate to escape a booking for two robust challenges on Yeremy Pino, before Chris Richards rattled the crossbar with a header from a corner.
The contest was as good as over eight minutes from half-time. Yeremy Pino weaved past a series of comically weak challenges before coolly slotting a shot past goalkeeper Wessel Speel to make it 3-0.
After the break, coach Oliver Glasner seized the opportunity to withdraw several individuals like Kamada and Wharton. Substitute Romain Esse came close to scoring with his first touch, but saw his shot blocked.
The youngster was incredibly unlucky later on, seeing one shot strike off both posts before being gathered on the line. Uche then blazed a glaring chance, indicating there is still scope for improvement in his game.
A solitary concern for Palace was a second-half knock to Justin Devenny, who was forced off. This paved the way for 17-year-old striker Benji Casey to earn his first-team debut, capping an otherwise perfect night for the traveling side.