Borussia Dortmund crashed to a 2-0 defeat at Augsburg on Saturday as Norway striker Erling Braut Haaland failed to rescue the visitors on his return to Bavaria, where he wrote Bundesliga history in January.
With defending champions Bayern Munich at Hoffenheim on Sunday, last season's runners-up Dortmund blew the chance to build on their impressive 3-0 win over Borussia Moenchengladbach last Saturday when Haaland scored twice in an electric display on the opening weekend of the season.
The 20-year-old has netted 18 goals in 21 games this year for Dortmund and wrote himself into Bundesliga history in January when he became the first player to score a hat-trick off the bench on his German league debut.
Haaland's three goals in 20 minutes sparked a 5-3 fight-back win.
However, the Norwegian hot-shot drew a blank on his return to Augsburg's WWK-Arena with just one clear shot on goal as centre-back Felix Uduokhai powered home a header for the hosts from a free-kick on 40 minutes.
Then former Schalke playmaker Daniel Caligiuri added to Dortmund's misery by holding off Thomas Meunier to fire home the hosts' second on 54 minutes.
Haaland was booked with a half an hour gone after some pushing and shoving with Augsburg defender Jeffrey Gouweleeuw, who was also shown a yellow card.
Dortmund had three times as many shots on goal and dominated with 80 percent posession, which left their Swiss coach Lucian Favre to admit, "we are very disappointed, it's hard to accept this defeat.
"We have much to do," admitted Favre, with one eye on Wednesday's German Super Cup match against Bayern in Munich.
"We almost completely dominated the game, we started well, but we weren't precise enough and were too hasty in our play.
"Augsburg defended well, we need to be more patient and play more down the flanks. "
- Stalemate at Leverkusen -
RB Leipzig were held to a 1-1 draw at Baver Leverkusen as Emil Forsberg's superb opening goal for the Champions League semi-finalists was cancelled out by an equally impressive long-range effort from Leverkusen's Kerem Demirbay.
Leverkusen's new signing Patrik Schick, who spent last season on loan at Leipzig, curled in a superb shot from 16 metres out but his stunning strike was ruled offside with 23 minutes left.
Borussia Moenchengladbach had to settle for a point at home to Union Berlin in their 1-1 draw.
Marcus Thuram's headed goal for Gladbach on 56 minutes was cancelled out by an equaliser from Union defender Nico Schlotterbeck, 20, making his Bundesliga appearance for the Berlin-based club, with 11 minutes left.
History was made in Arminia Bielefeld's 1-0 win at Cologne as Joan Simun Edmundsson, 29 came on to score the winner and become the first Faroe Island player to play and score in the Bundesliga.
Newly-promoted Stuttgart romped to a thumping 4-1 win at 10-man Mainz.
Sweden forward Robin Quaison scored early on for Mainz, but Congo winger Silas Wamangituka equalised just before half-time with his second goal in as many weeks after finishing a counter-attack.
Daniel Didavi added Stuttgart's second on 61 minutes after a simple tap-in, just before Mainz were reduced to 10 men when French centre-back Moussa Niakhate was shown a red card for a second booking.
The visitors profited with goals in the final 10 minutes through replacement Mateo Klimowicz and forward Sasa Kalajdzic as Stuttgart earned their first league win at Mainz for 15 years.