Three days before their German Cup quarter-final against Bayern Munich, Champions League competitors Dortmund failed to make their superiority in possession and firepower count.
They looked to be cruising to their sixth win in the last seven league games when Germany international Mario Gotze put them ahead in a dominant first half with a well-taken penalty.
Gladbach's Amin Younes cancelled out the visitors' lead against the run of play with only their second shot on goal midway through the second half. The 19-year-old's debut Bundesliga goal came in only his second appearance.
"We played a great away game for about an hour," Dortmund coach Jurgen Klopp told reporters. "We gradually played less football than we wanted, giving Gladbach the chance to come back."
"There are worse things than getting a draw at Gladbach but we are not really happy," said Klopp who knows their title defence is all but over.
The result left Dortmund 17 points behind leaders Bayern Munich, who crushed Werder Bremen 6-1 on Saturday.
Leverkusen failed to capitalise on Dortmund's slip-up, staying a point behind on 42 after a lethargic performance at battling Furth.
The hosts, with interim coach Ludwig Preis in charge after sacking Sascha Molders in the week, kept their first clean sheet since November to move up to 13 points, three behind 17th-placed Hoffenheim and five off Augsburg in the relegation play-off spot.
Dortmund's Gotze tried to charge through the defence several times before he latched on to a superb pass from former Gladbach player Marco Reus on the half hour and attempted to round goalkeeper Marc-Andre ter Stegen who lifted his boot to bring him down.
Gotze converted the penalty to give the visitors the lead in a one-sided first half in which Gladbach, missing gifted left-footer Juan Arango through injury, did not manage a shot on target.
They came close twice early in the second half with Younes volleying into the hands of Dortmund keeper Roman Weidenfeller and Austrian Martin Stranzl heading at the keeper from point-blank rage.
Younes was not to be denied, though, in the 68th minute, drilling in his deflected shot from just inside the box.
Pressure from Dortmund in the final 20 minutes did not pay off with Kevin Grosskreutz and captain Sebastian Kehl missing chances.
Peniel Mlapa fired into the side netting in the 89th minute as Gladbach almost snatched a late winner, something Dortmund also failed to do when Kehl fluffed his effort in front of an open goal seconds before the final whistle.
Get the best features, fun and footballing frolics straight to your inbox every week.
Thank you for signing up to Four Four Two. You will receive a verification email shortly.
There was a problem. Please refresh the page and try again.