His side thumped Feyenoord 4-0 in Rotterdam, and the Spaniard was well aware that the win has provided his side with a good foundation for the rest of the Champions League.
"It's so important to win the first game and though nothing is achieved yet, it's a great start for us this evening," said Guardiola.
"Last season we weren't able to win any games away in the Champions League and we spoke about that among the squad.
"If we want to be able to move forward, you must be able to win games away in this competition – home matches as well, of course – but we made a very good performance.
"We've made a huge effort to move forwards and brought in five players during the summer – as have all the top clubs in Europe – PSG, Manchester United, Chelsea, Barcelona - and it's important for us to see if we can go away from home with the same mentality we have at the Etihad.
"The same high press, attacking philosophy and not conceding on the counter-attack, so I'm very pleased tonight."