Niko Kovac was left stunned as FC Bayern München suffered a 2-0 defeat at the hands of Hertha Berlin at the Olympiastadion Berlin on Friday night.
A Vedad Ibisevic penalty on 23 kicked off proceedings, after Jerome Boateng had upended Salomon Kalou in the box.
Ondrej Duda then added a second on 44 as the Bavarians found themselves uncharacteristically wasteful in front of goal.
It was the club’s first defeat after being held by FC Augsburg recently where Kovac fielded a much-changed team.
Many of the leading names were back in Berlin, but Bayern were shaky in defence.
After the match, Kovac told his club’s website: “The conversion rate is one of the reasons why we lost. Besides, we conceded two goals we shouldn’t have allowed.
“We mustn’t concede a penalty like this, we made a tactical mistake before the second goal. If you make mistakes you get punished, that’s the way it is at this level.
“Still, we turned in a decent display.”
He added: “It’s hard to find an explanation. We must convert our chances, but we mustn’t start to decry everything. It just happens. Those who know Bayern will know we won’t accept it and do everything to return to winning ways.”
Manuel Neuer also had his thoughts on the loss, saying: “We weren’t 100 percent alert in the first half, we turned in a different display in the second half. Then you saw we absolutely wanted to win the match.
“Of course our conversion rate is a big issue, you also saw it in our last match. You just have to put it in up front, that’s football. It was missing again today.
“At half-time we were confident that if we score a goal in the second half we have a chance to turn the tide.”