Borussia Dortmund let a three-goal lead slip inside 15 second-half minutes as Hoffenheim claimed a 3-3 draw that could put a dent in the hosts' Bundesliga title charge.
Lucien Favre's men are winless in three matches in all competitions and the manner of their collapse in the closing stages against a physical Hoffenheim side will worry the head coach, who missed the match with a bout of flu.
Jadon Sancho scored his first goal of 2019 and his seventh of the season as the home side dominated the first half and he was instrumental when Mario Gotze struck.
A wonderful moment of skill from Sancho led to Raphael Guerreiro scoring Dortmund's third before Hoffenheim's comeback, which featured goals from substitute Ishak Belfodil and Pavel Kaderabek.
Dortmund failed to deal with Belfodil's imposing presence and he scored either side of Kaderabek's towering header to earn Julian Nagelsman's side a draw, opening the door for Bayern Munich to cut the gap to BVB to five points when they face Schalke later on Saturday.