After firing into the net in the second period of extra time on July 11, 2010, Iniesta tore off his shirt to show a white sleeveless vest emblazoned with the Spanish "Dani Jarque siempre con nosotros" (Dani Jarque always with us).
Seen by hundreds of millions of television viewers around the world, it was a tribute to Iniesta's friend and former Espanyol captain Jarque, who collapsed and died aged 26 on a pre-season tour of Italy in August 2009.
"With this gesture, Iniesta won the hearts of all blue and white [Espanyol] supporters," Espanyol said on Sunday in a statement on their website.
Iniesta presented the shirt to Espanyol last November and it has been put on display next to a mural remembering Jarque inside the stadium.
Visitors can see the shirt on matchdays and when taking one of the official tours of the Cornella-El Prat arena.
"Without doubt it will become one of the most prized and admired objects in our stadium for all that it represents," Espanyol said.
Iniesta was given two standing ovations by the home fans when his Barcelona team played at Cornella-El Prat in December in stark contrast to the usual hostile reception reserved for Espanyol's city rivals.
