Borussia Dortmund missed a golden chance to go top of the Bundesliga on Saturday when they surrendered the lead in a 3-2 defeat at Cologne.
Leaders Union Berlin lost at Frankfurt but Dortmund failed to capitalise just a week ahead of a match with defending champions Bayern Munich.
They led Cologne 1-0 at the break before conceding two costly goals in two minutes early in the second half to leave manager Edin Terzic lamenting his fragile side’s third Bundesliga defeat so far.
“It’s very disappointing for us – it’s very bitter,” said Terzic.
“We weren’t ready to show our toughness (in the second half).
“At one of the most important stages in the game, we were not ready to defend our goal.”
Cologne manager Steffen Baumgart – whose side have lost only once in the Bundesliga this year – praised his team for “a very good performance”.