Despite embarking on their first-ever continental campaign, Oliver Glasner's side are adapting very quickly. Without key players like forward Jean-Philippe Mateta and wing-back Daniel Muñoz, the Eagles departed Dublin with a comfortable win that virtually secures them a spot in the Europa Conference League qualifying rounds.
Another victory in their next fixture against Finnish KuPS ought to be enough to seal direct passage to the last 16, especially following a previous setback against Strasbourg.
This match offered a platform for some of Palace's lesser-used talent to impress. Christantus Uche, in only his second start after arriving on loan from Getafe, notched the account with a well-taken finish. Forward Eddie Nketiah contributed a second, scoring for the second game in succession.
A Shelbourne team that had concluded their league season were no match even for a mostly rotated Palace lineup. The Londoners were already weakened by the reports that Mateta and Muñoz are sidelined with leg injuries.
Despite heavy rain in Dublin, Palace quickly established dominance. A slick move in the 11th minute, sparked by Daichi Kamada's clever pass, let Nketiah to lay on Uche for a straightforward finish.
Youngster Adam Wharton went close soon after, fizzing a long-range effort over the bar. Nketiah subsequently claimed for a penalty after racing into the box, but the official waved away the protests.
The formerArsenal striker did not have wait long to get his goal, prodding home from a yard out after Uche's shot had struck the post.
Shelbourne were clinging on for dear life. Full-back Kameron Ledwidge was lucky to avoid a booking for a couple of robust challenges on Yeremy Pino, before Chris Richards struck the crossbar with a header from a corner.
The contest was effectively over eight minutes before half-time. Yeremy Pino meandered past some comically weak challenges before calmly dispatching a shot past keeper Wessel Speel to extend the lead to 3-0.
After the break, coach Oliver Glasner seized the opportunity to rest key individuals like Kamada and Wharton. Replacement Romain Esse came close to scoring with his first touch, but saw his effort blocked.
Esse was desperately unlucky later on, seeing one attempt crash off each posts before being clasped on the line. Uche also blazed a glaring chance, indicating there is still room for improvement in his game.
A solitary worry for Palace was a late injury to Justin Devenny, who limped off. This allowed 17-year-old forward Benji Casey to make his senior debut, rounding off an otherwise positive night for the traveling side.