Iniesta left Chelsea heartbroken back in 2009 when his stoppage-time strike earned Barca a 1-1 draw in London and saw the Catalan side progress through to the Champions League final instead of the Blues on away goals.
Chelsea now have the chance to gain revenge over Pep Guardiola's reigning champions when they clash again in this year's semi-finals and, speaking ahead of Wednesday's first leg at Stamford Bridge, Iniesta knows the Barclays Premier League side will again be no pushovers.
"It's painful to be knocked out so close to the final. Now we are facing each other again and undoubtedly their desire to beat us and be in the Champions League final will be significant," Iniesta said on Monday.
"We hope that things will turn out well for us again this time.
"We are going there with the intention of winning, to have a good game and commit as few mistakes as possible, as in the Champions League they are very costly. We always go out to win. We know that it is a knock-out tie and there is a return game, but our only intention is to win.
"It will be a tough 90 minutes. Chelsea are more experienced now, inevitably, and they have also changed some players. They have Fernando (Torres), (Juan) Mata and some other young players. Chelsea were very strong that year and the will be this year as well.
"They are very dangerous, very intense, and that will by multiplied in their stadium due to the atmosphere. We are expecting a very tough tie."
Iniesta also warned of the threat posed by some of Chelsea elder statesmen, such as Didier Drogba and Frank Lampard.
"They are dangerous for who they are, not because they are older or that it could be their last opportunity to win the Champions League. You have to respect them because they are great players and right now are in a very good moment. I think it's going to be a very nice tie," he added.
The trip to Chelsea starts what could be a key week in Barcelona's season, with Real Madrid visiting the Nou Camp in the Primera Division this weekend before the Champions League second leg takes place next Tuesday.
Barca have won 11 successive matches in the Primera Division to cut Madrid's lead at the summit back from 10 points to four heading into the final five rounds of the season, and the destination of this year's title could ultimately rest on the outcome of Saturday's 'Clasico'.
"It's a key and very important week. That's the reality. We are playing to get into a Champions League final and we are playing to extend the battle for the league," said Iniesta, who insisted his side's attention was only on Chelsea and not on Madrid.
"We are 180 minutes from a Champions League final. Our thoughts and focus have to be on the game against Chelsea. On Thursday we will start to think about the Clasico against Real Madrid.
"In the Champions League we depend on ourselves and in the league we depend on the leaders slipping up. We have to be right up there in case they do.
"We are in the final straight and if it has been difficult up to this point, then what is left ahead of us will also be difficult."