Robert Mancini's side have endured some indifferent results of late - most significantly a 3-1 defeat at Southampton on February 9 - but Aguero scored twice to help them to make the FA Cup quarter-finals in style.
The Argentina international told City TV: "This helped us to do things well and give us confidence for the Chelsea game. It will be a good match, difficult, but obviously we need to go out and win.
"I think against Southampton none of us played well and it was a bad day for us all - an error which we hope not to repeat.
"We will try not to lose any more points in the league so we can keep all three points. I think we've played well and reached the next round. We need to continue like this."
On his own performance, Aguero added: "Yes, I had a great game. The whole team played well though. The important thing was to win and we did. So now we will have a bit of calm and can concentrate on the Chelsea game.
"Yes, they were two good goals but the most important thing was they helped us to win. So I'm happy for the goals and for the win.
"I really like this cup, played as a single leg. Obviously if we maintain our concentration, I think we have a team that can reach the final."