Stefano Pioli insists Lazio cannot take anything for granted after earning a "small advantage" with a 1-1 draw away to Sparta Prague in the first leg of their last-16 Europa League tie.
The home side took the lead when Martin Frydek found the net with a rising drive after 13 minutes, only for their Serie A opponents to peg them back before half-time with a goal from Marco Parolo.
The result puts Lazio - who lost to Inter in the 1998 UEFA Cup final - in a promising position to reach the last eight of the competition, although Pioli acknowledges there is still work to do on home soil.
"We wanted to get a small advantage from the first leg away from home and we did that. We're strong at home, but Sparta Prague are not to be underestimated on their travels either," he told Sky Sport Italia.
"We started the game well and had some good chances, but were caught too open on their goal. The positive thing is the reaction we had, showing real character.
"Now we can look ahead to the second leg, which will also be very balanced. It is only a small advantage."
Midfielder Parolo, who turned home a loose ball after 38 minutes to make it 1-1, agreed with his coach, although he hopes history will repeat itself in the second leg.
Lazio also recorded a 1-1 result away to Galatasaray in the last round of the tournament - then went on to win the return fixture 3-1 in Rome.
"Like in Istanbul, we have a small advantage and can now fight it out on home turf for qualification," Parolo told Sky Sport Italia.
"Qualification in Europe is never easy, so we have to be wary. Sparta can cause us problems and we need to play with intensity in the second leg."