The Brazil international has hailed the importance of the attacking midfielder\'s strike at Stamford Bridge nearly two years ago, and added that the Blaugrana are not invincible.Barcelona defender Dani Alves has lauded the crucial impact of Andres Iniesta\'s goal against Chelsea in the semi-finals of the 2008-09 Champions League.The Catalans were on the brink of elimination when Iniesta found the net well into stoppage time to help Pep Guardiola\'s men to a 1-1 draw at Stamford Bridge after a scoreless affair in the first leg, thus firing the Blaugrana into the final against Manchester United.As both sides prepare to meet again at the very same stage of the Champions League this term, Dani Alves looks back to the match in 2009 and feels that Iniesta\'s goal was the start of Barcelona\'s dominance in both Spain and Europe.\"This memory will never be erased. It’s the goal that led us to the final and thanks to that goal we went all the way and won this title,\" the right-back was quoted as saying in the Daily Mirror.\"This goal gave us confidence and faith in what we were doing. And it formed the basis of our success in our quest to win trophies.\"It’s inevitable that I remember that moment with a great deal of importance.\"Dani Alves then went on to stress that Barcelona are not invincible, but added that they\'re very hard to beat if they get to play their own game.\"We are not invincible. But when we are at our level, it’s extremely difficult to beat us. We want to win this competition again and defend our title but we know it’s difficult to achieve it. \"We have ambition to retain our title knowing that each year it’s more difficult and more complicated. But, faced with difficulties, Barcelona always responds as the great team that we are.\"The first leg of the semi-final between Chelsea and Barcelona takes place at Stamford Bridge on April 19.