The young goalkeeper threw away his side's lead in incredible fashion as he knocked a simple pass into his own net
Gladbach took the lead through Braunschweig goalkeeper Marjan Petkovic who put the ball in his own net, but the Barcelona target was desperate not to be outdone and ensured he got one up on his opposite number by driving the ball over the line to square things up in a hilarious blunder.
The 21-year-old, who is reportedly close to agreeing a move to the Catalan giants, failed to control a simple Filip Daems backpass and inadvertently knocked in the equaliser for Torsten Lieberknecht's side.
Ter Stegen's exploits ruined Gladbach's chances of ending their seven game winless streak. The draw, combined with Mainz's win over Bayer Leverkusen, also saw die Fohlen surrender the Bundesliga's final Europa League spot.