The 33-year-old, whose future beyond the end of the current season is in doubt, played 83 minutes of the clash as Barca kicked off their European campaign in style.
Iniesta bagged a key assist for his side's second of the evening and showed signs of his previous best form, offering encouragement that he could offer more than last term when featuring just 23 times in the league.
Speaking to TV3 after the match, the Spanish midfielder said: "I am happy to have started the competition with a win and feeling good against an always tough opponent.
"With Luis Enrique [last season], the way he had to manage it was shared. The coach always wants what is best for the club. The important thing is to train well and to have no setback."
Iniesta has now started Barca's last two matches, while also featuring twice for Spain during the recent international break.