The Blues played with an aggressive pressing style against the Ukrainian champions, establishing a 3-1 first leg lead.
Aguero took his season tally to 19 with the opening goal in Kyiv, though has warned it would be dangerous to believe the tie is over.
“It is always important to win the first leg and, of course, we are very happy,” said Aguero. “It’s a good result but we still have a lot of work to do at home.
“I think we have to keep playing in the same way we did against Kyiv in our remaining games.
“First we must qualify for the next round by completing the job at the Etihad and if we do that, then we’ll see what happens in the draw.
“I think it will be an open game in the second leg because they have no other option but to go for the win.
“If that’s the case, they will leave plenty of space, which is of course much better for us, but as I say we have to keep playing the way did in the first leg and also take that energy into our other games.”
