Despite embarking on their first-ever continental campaign, Crystal Palace are learning at a rapid pace. Missing star figures like forward Jean-Philippe Mateta and wing-back Daniel Muñoz, the London club left Dublin with a commanding win that virtually guarantees them a place in the Conference League playoffs.
A further victory in their next match against Finnish KuPS should be sufficient to seal direct passage to the last 16, particularly following a previous stumble against Strasbourg.
This occasion offered a platform for several Palace's fringe talent to shine. Christantus Uche, making only his second start since joining on loan from Getafe, opened the scoring with a well-taken finish. Forward Eddie Nketiah contributed a second, scoring for the second game in succession.
The Shelbourne team that had finished their league season were no match against a mostly rotated Palace lineup. The visitors were already weakened by the reports that Mateta and Muñoz are out with leg problems.
Despite torrential rain in Dublin, Palace quickly took control. A slick move in the 11th minute, sparked by Daichi Kamada's incisive pass, let Nketiah to set up Uche for a straightforward tap-in.
Youngster Adam Wharton went close soon after, fizzing a powerful effort over the bar. Nketiah subsequently claimed for a penalty after racing into the box, but the referee waved away the protests.
Ex-Arsenal striker did not have wait long to get his goal, prodding home from close range after Uche's effort had struck the post.
Shelbourne were hanging on desperately. Full-back Kameron Ledwidge was fortunate to escape a booking for a couple of agricultural challenges on Yeremy Pino, before Chris Richards struck the woodwork with a powerful header from a corner.
The match was as good as over eight minutes from half-time. Yeremy Pino weaved past some weak challenges before calmly slotting a shot past keeper Wessel Speel to extend the lead to 3-0.
After the break, manager Oliver Glasner seized the opportunity to withdraw several individuals like Kamada and Wharton. Replacement Romain Esse came close to scoring his first touch, only to see his shot blocked.
The youngster was incredibly unlucky later on, seeing one attempt crash off each posts before being gathered on the line. Uche then missed a glaring chance, indicating there is still scope for improvement in his game.
A solitary concern for Palace was a second-half injury to Justin Devenny, who was forced off. This paved the way for 17-year-old forward Benji Casey to make his senior debut, rounding off an otherwise positive evening for the traveling side.