Heidenheim's on-loan midfielder Eren Dinkci scored twice in a 4-2 win against his parent club Werder Bremen on Sunday to give the promoted side their first ever Bundesliga victory.
Bremen-born Dinkci, who joined Heidenheim on loan from Werder in July, scored either side of half-time as the Bundesliga newcomers prevailed in a six-goal thriller.
"It's a great feeling. My first brace in the Bundesliga, and it comes against Bremen of all clubs. My whole family is here today, so it doesn't get much better than this," Dinkci told DAZN.
The club's first top-flight win came on a weekend when coach Frank Schmidt celebrated 16 years in the dugout, making him the longest-serving coach in German league history.
Schmidt took over Heidenheim in the fifth tier back in 2007, but he dismissed talk of a fairytale on Sunday.
"There was nothing cheesy about today's win, it was just an awesome game of football," said the no-nonsense Heidenheim boss.
Tim Kleindienst gave Heidenheim an early lead from the penalty spot after Bremen's Anthony Jung threw an elbow at the ball while defending a free-kick.
The home side then doubled their advantage on the stroke of half-time through Dinkci, who refused to celebrate after smashing the ball past former teammate Jiri Pavlenka in the Bremen goal.
The visitors looked down and out at half-time, but were given a route back into the game thanks to an Omar Traore handball minutes after the restart.
Marvin Duksch hit the resulting penalty straight at Heidenheim goalkeeper Kevin Mueller before nodding the ball in on the rebound to make it 2-1.
Bremen missed another good chance to equalise through Romano Schmid before Mitchell Weiser finally pulled them level with a well-placed header on 64 minutes.
Dinkci restored the lead just four minutes later, slotting the ball into the bottom corner from the edge of the area after a cross from Jan-Niklas Beste.
Beste, who also spent a year at Bremen's reserves in 2018/19, rifled in a fourth a few minutes later to seal the win.