Deniz Undav scored a brace as a rampant VfB Stuttgart put on a spectacular display to shock Borussia Dortmund 5-1 at home on Sunday, handing Nuri Sahin's side their first defeat of the Bundesliga season.
Eighth-placed Dortmund are level on seven points with Stuttgart, who sit one place higher thanks to a better goal difference, ahead of Sunday's remaining fixtures.
Undav got Stuttgart off to a flying start inside five minutes at the MHP Arena when the forward found left back Maximilian Mittelstadt's pass, stormed into the box and fired the ball into the far bottom corner.
He nearly made it 2-0 within seconds to continue his goal-scoring form, which has seen him score five goals across all competitions this season with the latest coming in their 3-1 defeat at Real Madrid in the Champions League, but he failed to time his shot.
Last season's runners-up tore apart the stunned visitors' defence, with Mittelstadt providing Ermedin Demirovic with a chipped cross to head home and double their lead in the 21st minute. It was Demirovic's second successive league goal.
The hosts piled on the pressure and carved out several chances, with Dortmund goalkeeper Gregor Kobel making a stellar double save to deny Frenchman Enzo Millot's powerful volley from distance and Undav on the rebound.
But Mittelstadt's short corner found Atakan Karazor, who headed it back across the goal for Millot to tap in from close range and make it 3-0 for Stuttgart in the 62nd minute.
Dortmund did not pose a challenge to Sebastian Hoeness' Stuttgart, who were sharper and more aggressive.
Former Stuttgart man Serhou Guirassy reduced Dortmund's deficit with a goal in the 72nd minute, but substitute El Bilal Toure and Undav made matters worse as they added another goal each to Stuttgart's tally to make it 5-1.
Stuttgart had beaten Dortmund home and away in the Bundesliga last season as well as the German Cup.