Peter Bosz's first game in charge of Borussia Dortmund ended in a shock defeat as the Bundesliga giants went down 3-2 in a pre-season friendly at fourth-tier side Rot-Weiss Essen.
Pierre-Emerick Aubameyang was named in a strong team and scored as speculation continues to intensify about his future, although Mario Gotze was not included in the squad as he continues to recover from a metabolic disorder.
Bosz's reign got off to a poor start when Essen took the lead in the third minute, Benjamin Baier cutting inside off the left wing and picking out Roman Burki's bottom-left corner from 25 yards with a superb strike.
Aubameyang equalised on the half-hour mark, however, the in-demand striker tapping in at the back post after Andre Schurrle's left-wing corner was flicked on by Omer Toprak.
Baier restored the hosts' advantage five minutes before half-time by thumping a 20-yard drive through Burki's grasp after Kamil Bednarski's miscued shot fell kindly.
Bosz made 11 changes at the interval and his side fell even further behind when an unmarked Marcel Platzek turned in Kevin Grund's wicked set-piece delivery.
Dortmund quickly reduced the deficit from the penalty spot, Ousmane Dembele coolly converting from 12 yards after Grund's handball.
Christian Pulisic and Alexander Isak went close to scoring equalisers for the visitors, but Bosz's Dortmund debut ended in an embarrassing loss.