The midfielder won the respect of Espanyol supporters when he scored Spain's winning goal against Netherlands in the final in South Africa back in July.
The 26-year-old ripped off his shirt in the celebrations to reveal a vest with a dedication to Jarque, who had died of heart failure aged 26 last year. The two had been good friends.
Espanyol fans gave him a standing ovation when the team sheets were read out before kick-off, and again when he was substituted near the end of the match.
"I felt it on the pitch, this is biggest thing, people have sent me messages... people are more important than rivalries," Iniesta, a shortlisted candidate for this year Balon d'Or award, told reporters.
His coach Pep Guardiola said: "Andres deserves it and I would like to congratulate the stands at Cornella-El Prat for the way they treated him."
La Liga leaders Barca won the game 5-1, the support for Iniesta standing out in stark contrast to the usual hostile reception reserved for the rest of Barca's team.
