A 2-2 draw on the night sealed an aggregate victory for the Blues and their interim coach was thrilled by the character that they showed in reaching the final in Munich
The Blues drew 2-2 at Camp Nou despite having captain John Terry sent off, progressing 3-2 on aggregate, with Ramires and a stoppage-time effort from Fernando Torres sealing the triumph.
"It’s an incredible achievement by this group of players. A lot of people had written us [off] but we showed again what kind of character these players have," Di Matteo told Sky Sports after the game.
"We didn’t expect to play with 10 men, but we knew it was going to be tough and it was even more difficult than we expected. Barcelona have some fantastic players but we showed what we’re made of.
"The second half wasn’t much about tactics – it was about the pressure, the pride, the desire to go to the final. We were 45 minutes away from the final and that’s what the second half was about.
"The belief was always there - we wouldn’t be in the final if we didn’t believe we could get there."
Terry had been red-carded just after Barca took the lead on the night through Sergio Busquets, having appeared to knee Alexis Sanchez in the back off the ball, but had apologised after the game, and Di Matteo was in a forgiving mood.
"He’s a fantastic leader of this group and he’s the captain of our club," he insisted.
"Everybody can make a mistake in life and we’re just so happy that this group has managed to go to the final. I’m not angry with him. We’re all human beings. They’re under a lot of pressure, these players."
When asked about Terry, Ramires, Branislav Ivanovic and Raul Meireles all incurring suspensions to miss the final, the Italian replied: "Let’s enjoy it for a moment.
"We achieved something incredible tonight and when it’s the right time we’ll think about the final.
Ramires' delightful chip just before half-time provided a timely boost just when events were starting to get away from Chelsea, a moment the importance of which Di Matteo recognised.
"It was a crucial goal. We said it before the game that we needed a goal and we managed it," he noted. "With the goal, the advantage was back with us."