Thomas Tuchel praised his men, especially goal scorers Mason Mount and Ben Chilwell, following their victory in Estadio Ramón Sánchez Pizjuán.
"It was a tough match against a strong Porto side,"
The Blues boss told BT Sport.
"There were many moments where we suffered. We accepted it. The circumstances are a bit different in a quarter-final. The spirit was good and it was an excellent result.
"I was pretty sure about that [they'd react well after the WBA defeat]. I saw a response immediately in the dressing room and the next day. That wasn't a big concern. We were ready to respond. There will always be setbacks in sports. The biggest challenge is to bounce back.
"We had a lot of excellent results together, then we had a loss together and then a reaction after a loss together. That brings us closer together and increases the trust."
Mason Mount scored the first goal in the first half, while Ben Chilwell added the Blues' second before the final whistle.
"I'm very happy that he [Mount] scores,"
. "A very important goal that opened up the game. It calmed the nerves. Not an easy shot but very precise. Very happy for Mason. He took responsbility.
"[Chilwell's goal was] excellent. He kept composure and went round the keeper. It was super important to get the second away goal. Chilly forced the mistake and kept his cool in the box. We're very happy to go away with this result but it's only half-time."