Borussia Dortmund slumped to a 2-1 defeat at Augsburg in the Bundesliga on Saturday and were left with 10 men as they suffered a second defeat in five days.
Alexis Claude-Maurice struck twice for Augsburg as Dortmund lost again after Tuesday's 5-2 reverse away to Real Madrid after wasting a 2-0 lead in the Champions League.
Dortmund, Champions League finalists last season, have not won any of their four away games in the Bundesliga this season and remain in seventh place on 13 points after two defeats and a win in their last three league games.
The latest loss also piles the pressure on coach Nuri Sahin, in his first season in charge, after he was heavily criticised for his team wasting their 2-0 lead over Madrid and conceding five goals in the second half.
"Eighty percent possession does not necessarily mean more chances. We just did not get into the danger area often enough," Sahin told a news conference.
Dortmund had more than 70% possession throughout but hardly had any scoring opportunities for more than an hour after their 1-0 lead in the fourth minute.
"[The] fact is for 80% possession we had far too few chances. We need to work on creating more chances," Sahin said. "Our squad is not without experience and I expect all of us together, players and coaches, to face this current situation and go through it together."
RB Leipzig provisionally took over top spot on 20 points with a 3-1 home victory over Freiburg. Bayern Munich, who are in second spot on 17, are in action at VfL Bochum on Sunday.
Dortmund had the perfect start as they struck on the break with Donyell Malen slotting in for a fourth-minute lead.
But there was little else that came from the Dortmund attack in the first half and Augsburg got an unexpected equaliser in the 25th when Claude-Maurice broke through, found no resistance from four players and lots of space to drill in from 25 metres.
The Frenchman, making his first league start for Augsburg, netted a second to complete the comeback five minutes after the restart, curling a low shot home from the edge of the box.
Dortmund, who are in action in the German Cup against VfL Wolfsburg next week, had substitute Almugera Kabar sent off for a second booking on his league debut in stoppage time.
They also had to take off Waldemar Anton and Julian Ryerson due to injuries.