After a tense first-half against Rayo Vallecano, Palace flew out of the traps after half-time, overwhelming the Spanish side with waves of attacks.
In the 51st minute Wharton picked up the ball and drove at the Rayo defence, with different options opening up for him.
His shot was saved but fell perfectly for Jean-Philippe Mateta to find the net and get the all-important breakthrough.
After lifting the trophy, Wharton took a brief break from the celebrations to explain his decision-making at that moment.
