"I recognise this team when they play together, when they play as a team. If we play this way, I am not surprised," he said.
"I am surprised when we concede three times from a corner on Saturday. Then I am surprised.
"I spoke a lot about corners and to maintain a clean sheet and my players tonight were very concentrated, strong and attentive in every situation. It was good for everybody after the bad defeat in Manchester.
"We showed a very good attitude, character and personality during all of the match. Also during the last minutes when Porto tried to equalise, we were very calm, very attentive and closed all of the space."
Leicester sit on top of Group G with two wins from their first two matches in the Champions League.