Julian Nagelsman slammed 10-man RB Leipzig for defending like "a school team" in Wednesday's 2-2 draw at home to Hertha Berlin behind closed doors which cost them the chance to go second in the Bundesliga.
Hertha forward Krzysztof Piatek equalised with a late penalty to seal the draw and save the blushes of goalkeeper Rune Jarstein who had made a blunder for Leipzig's second goal.
However, Nagelsmann was furious that Leipzig conceded a weak goal from a corner with only nine minutes gone when Hertha midfielder Marko Grujic, on loan from Liverpool, fired home unmarked.
"We started well, but fell behind because we defend a set piece like a school team," fumed Nagelsmann.
"We simply did nothing, everyone is standing in position, yet he (Grujic) could finish with his foot, in the box.
"This is the second time in a row in a home game that we conceded from a set piece," said Nagelsmann whose team drew 1-1 against Freiburg in their last home game.
"We have to blame ourselves for this. We're happy that we scored another point, but I'm not happy at all."
Piatek, who joined Hertha in January from AC Milan, netted his second goal in nine Bundesliga matches when he fired home a penalty on 82 minutes.
"I was feeling good, it was an important goal for me and the team," said Piatek, 24, who came on for the final twenty minutes, replacing 35-year-old striker Vedad Ibisevic.
Piatek stepped up to take the penalty just after Ibisevic had been substituted.
"I'm not happy, I want to play. He is in great form, but I hope to play some more minutes," added Piatek when asked about his under-study role to Ibisevic.
The Polish striker slotted home after team-mate Matheus Cunha was fouled in the box by a rash challenge from ex-Everton winger Ademola Lookman.
Piatek's penalty snatched a point, stretched Bruno Labbadia's unbeaten record as Hertha head coach to three games and spared the blushes of Jarstein.
The Norwegian shot-stopper was embarrassed when he parried an effort by Leipzig striker Patrik Schick but allowed the ball to roll over his flailing arm and into his net to make it 2-1 on 68 minutes.
Leipzig had just been reduced to 10 men when defender Marcel Halstenberg was sent off for a second yellow card after a late foul on Brazil Under-23 striker Cunha, who was playing against the club he left in January.
The first-half finished 1-1 after Hertha took an early lead when Grujic, on loan from Liverpool, volleyed into the top corner with nine minutes gone.
The hosts fought back and equalised when defender Lukas Klostermann headed home a corner with 24 minutes gone.
The result leaves Leipzig third in the table, two points behind Dortmund, who lost 1-0 on Tuesday to leaders Bayern Munich who are seven points clear and on course for an eighth straight German league title.
"Today it (three points) was on a silver platter and we didn't take it," added Nagelsmann.