Lazio head coach Stefano Pioli has claimed that his side will need to improve if they are to reach the group stage of the Champions League.
Keita Balde Diao's 77th-minute strike earned Lazio a 1-0 victory in the first leg of the qualifying clash at the Stadio Olimpico, and despite taking a crucial lead into next Wednesday's meeting in Germany, Pioli has challenged his players to produce a better display.
"It was a difficult and complicated match," he told reporters. "Leverkusen played direct and aggressive football. We made some mistakes, but playing Leverkusen is not easy. We could have scored more but the result is certainly positive.
"The result does not change much for the return leg – there is still a battle to be fought. Lazio want to play in the UEFA Champions League and we showed that tonight too, but we have to improve if we want a positive result at the BayArena next week."
Lazio have not qualified for the group stage of the competition since 2007.