The dud, which is thought to be from the Second World War, was discovered late on Thursday morning during planned buildings works at BVB's Signal Iduna Park.
The VIP area of the west stand is currently being renovated, and the bomb was spotted in aerial photographs.
An 250m radius around the bomb was immediately evacuated, and a press conference in advance of the the local derby against fierce rivals Schalke was postponed. The crunch match is still expected to go ahead as planned on Saturday.
Once the area was cleared, disposal units from the Kampfmittelbeseitigungsdienst (KMBD) moved in to begin their operation.
#dobombe der Evakuierungsradius um den Fundort beträgt 250m, weitere Infos & Karte: http://t.co/DRTA8lW3Xk pic.twitter.com/TBgZ4qG5Uw
— Stadt Dortmund (@stadtdortmund) February 26, 2015
Trains passing the football ground were cancelled and several flights had to be diverted while the defusal was going on.
The 45-minute defusal operation ended at 3 pm, with local authorities announcing that the detonator had exploded at the time the bomb landed, but failed to set off the main charge.
Local reporter Jana Schoo tweeted a picture of the dud in the bomb disposal van.
Da ist das Dingen #dobombe #bvb #derby kann kommen 🙂 pic.twitter.com/VaK0OVfC1V
— Jana Schoo (@JanaSchoo) February 26, 2015
After the successful disposal, the city management tweeted: "The air-bomb has been defused! The most beautiful stadium in the world remains unscathed!"
#dobombe Die Fliegerbombe wurde entschärft! Das schönste Stadion der Welt blieb unversehrt! Zum Glück!! @BVB pic.twitter.com/2HTw4MXhGb
— Stadt Dortmund (@stadtdortmund) February 26, 2015
At the rescheduled press conference at BVB's training ground, manager Jürgen Klopp said: "I hope that there any more duds on the pitch on Saturday".
Signal Iduna Park is the largest ground in the Bundesliga, and manages to pack in up to 80,000 fans on match days.
The dud is of British origin, and was likely dropped during heavy bombing raids against Dortmund by the British Royal Air Force (RAF) in 1943.
by Matty Edwards
SEE ALSO: 3,000 WW2 bombs still under Berlin