Adi Hutter apologised to supporters after his Borussia Monchengladbach team were trounced 6-0 at home by Freiburg, with all six goals coming in a remarkable first half.
High-flying Freiburg became the first team ever in the Bundesliga to score five goals away from home inside the opening 25 minutes of a match, and Gladbach midfielder Patrick Herrmann bemoaned "a catastrophic performance".
Maximilian Eggestein and Kevin Schade put the visitors two up with only five minutes gone, before Philipp Lienhart, Nicolas Hofler, Lucas Holer and Nico Schlotterbeck got in on the act to shock those in attendance at Borussia-Park on Sunday.
Gladbach had previously been the only side to score five goals in the opening 25 minutes of a match, that coming at home to Braunschweig in October 1984.
The loss leaves Gladbach in 13th place in the Bundesliga, with just 18 points from 14 games, and head coach Hutter made clear after the game that it was an unacceptable performance and result.
"I am incredibly disappointed," Hutter told the official club website. "I'm also very sorry for the spectators who made their way to the stadium. We win together and we lose together.
"A few weeks ago, we beat Bayern 5-0 here and we were all over the moon. Today, we saw a match that should never have played out the way it did. Of course, we knew that Freiburg are strong from set-pieces and we prepared for that in training, but I had the feeling that we were paralysed from them.
"I don't have an explanation for that right now. First and foremost, we have to apologise for the way we played today. That is unacceptable. If you saw the level in training, you would never imagine that a performance like that could happen. But then when you're 5-0 down after 25 minutes, it's obviously very disconcerting."
25- SC Freiburg has become the first away team in BL history to score five goals in the first 25 minutes. Before that, only Gladbach had managed this at home against Braunschweig in October 1984. Historic. #BMGSCF pic.twitter.com/Xfivfgltx4— OptaFranz (@OptaFranz) December 5, 2021
Sporting directer Max Eberl also spoke to the club website, making mention of the Foals' "lethargy", saying: "We conceded two early goals, and you could see how nervy it made everyone. No one wanted the ball, although, to be honest, we didn't have much of the ball in the opening period anyway.
"We just had this inexplicable lethargy and didn't carry a threat at all. I'm a bit bewildered right now. Tomorrow is about picking ourselves back up and digesting the defeat. We conceded four goals in Cologne, and now six today, but we also didn't do enough going forward with enough incisiveness either."
Gladbach's Herrmann simply added: "It's hard to put the game into words. We had already thrown it away after a matter of minutes. We just weren't at the races at all in the first half – it was a catastrophic performance. If you're 4-0 down after 20 minutes and then concede the fifth goal, everyone knows that the game is over."