The Catalan giants fought back from a two-goal first-leg deficit at Camp Nou, silencing their critics with an imperious victory which sees them progress to the quarter-finals
David Villa bagged the third and decisive goal for the Spanish side after two goals from the majestic Lionel Messi, before Jordi Alba wrapped up the victory in stoppage time - with no reply from the visitors.
"We were lucky to score early and that helped us a lot," Pique told reporters.
"The atmosphere was amazing, the fans know we need them and for them we played well.
"We were better than Milan from the start tonight and fortunately we managed to score the goals to qualify."
Villa then spoke of the confidence flowing through the Barca team after such a heroic victory, as the Catalan side overturned Milan's two-goal lead and kept a clean sheet.
"The fans were always behind us, they always trusted us," he added.
"They knew we could do it and in the end we did it for them. When you go through a night like this all of the bad days are forgotten.
"After experiencing what we did tonight we don't care who we get in the quarter finals.
Jordi Alba echoed Villa's thoughts, believing that a continuation of their intensity and form is vital to their fight towards European glory.
"This was a very important victory for us," he told reporters.
"We were very good defensively and going forward. We knew exactly how to play this game tonight.
"We will look to continue with the same intensity in the next round."