Goals from Sergio Aguero and David Silva, plus a third consecutive clean sheet, made for a happy manager after full time at the Riverside.
Guardiola said: “We are so happy to be there (in the semi-final). We’ve played most of our games away against three teams from the Premier League and one of the best in the Championship so it’s a huge complement to the team.
“We made a good performance, we were there from the beginning. The game should be over 30 minutes before but we missed a few chances.
“It was similar for Middlesbrough at home, we created a lot of chances in the first half but didn’t score. Maybe you need that to improve, to get better. We’ll recover now and get ready for the game in France.
“When you attack good, you defend good. We defend 40m away, we want to play in that way. I always believe that when the ball is far away from our goal, we are safe.
GOALDEN VISION: Sergio Aguero wheels away in delight after scoring
“It’s good for the team for their confidence, not just the goal but before the two or three chances they had. Claudio (Bravo) made another good performance, three or four saves and that’s why we were able to have another clean sheet, it’s really good for us.”
There is little time to reflect on the victory with Wednesday’s Champions League last 16 second leg game against Monaco looming large.
Guardiola added: “I’m confident ahead of Monaco, but not for the result. I’m confident because I am pleased the most as I like to work with these guys, I’m so happy.
“The training is always happy. We’d like to go through, but we cannot forget the team we are going to play.
“Their attack is the best, by far. In terms of results, I think they’ve scored 100 goals in all competitions. It will be tough but we’ll try to play our game and try to be one of the best eight teams in Europe.”
