The 49-year-old was pleased with his side's character after Libor Kozak netted a 94th-minute equaliser to level a thrilling tie at Borussia Park
Libor Kozak scored in the 94th minute to level the scores for the 10-man Biancocelesti, after Thorben Marx and Juan Arango had turned the match on its head during an enthralling final ten minutes.
Petkovic was left frustrated at the manner in which his side conceded goals, but was delighted with the character they displayed during an end-to-end encounter.
“It was a bit crazy at the end, as we dominated the match for so long and I am happy we played good football for 90 minutes,” he told reporters after the match.
“We suffered too much on set plays, which doesn't happen to us every day. Kozak came on for the second half and certainly gave us the necessary push and created more space for Sergio Floccari.
“In the first half we tried, but after the first goal, we started to get passes wrong and lost our way. The team has great character and we saw it by the way they played right to the end for the result.
“I am very happy to have rediscovered the Lazio I last saw a few months ago. We are alive, playing good football and I hope we can take the same approach in the second leg with numerous fans putting pressure on the visitors the way we experienced it in Germany.”