The Round of 16 tie will be decided at the Etihad Stadium when the two Clubs face each other again on Tuesday 14 March following the 1-1 draw in Germany.
After Riyad Mahrez put City ahead in the first half, RB Leipzig levelled after the break, through Josko Gvardiol to keep the tie in the balance.
“I had the feeling that the game would be like this and it would be decided in the second leg,” Guardiola said.
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“I would say before they scored, that for 20/25 minutes they were excellent.
“Normally, there is one concept in football that if we play like in this in the first half people will say how bad we played in the second.
“Why can you not think that Leipzig is a good team? They have not lost many games, they beat Real Madrid here in a good game. The game against Bayern Munich, Bayern was better but in the second half Leipzig was much better.
“I have a lot of respect about Leipzig and when they do good things it’s because they are good.”
It was the third of five successive away games with Bournemouth in the Premier League and Bristol City in the FA Cup still to come.
The run started with a win at leaders at Arsenal and a draw at Nottingham Forest in a tricky run of fixtures.
And with Aymeric Laporte and Kevin De Bruyne missing through illness, Guardiola was delighted with the performance.
“Our game at Arsenal was really tough and after three days we played at Nottingham where we played really good,” he added.
“After that we came here, after that we have to go to Bournemouth to play Premier League and just three days later we go away again with some injured players.
“That’s why I put all this perspective. I am so delighted with the game we played. In three weeks hopefully we can arrive in good condition.
“Of course I will learn from what I saw today, we can do better, we can adjust something in the build-up because they are a really good team and find a way to get through.
“It’s Champions League, big clubs are in the Europa League right now so it’s such a demanding competition. Before it was quite easy but now today, all the teams in all leagues are really strong. Good teams, good managers.
“My expectations are not high. My expectation was not to fly to Leipzig to win easy. Not for one second I thought that, the game we are going to play needs control. It’s two legs, 180 minutes.”
