The 18-year-old Isak scored and set up a goal on his first start for the club with star striker Pierre-Emerick Aubayemang rested by the Cup holders.

Isak signed in January from Stockholm club AIK for a reported €9 million.

Dortmund hope the Sweden international, who had previously only made four substitute appearances for the side, can grow to become Aubameyang's future replacement.

Isak laid on a goal for Gonzalo Castro, who scored with his first touch of the ball on 42 minutes, then showed ice-cool finishing by slotting home on 47 minutes.

The floodgates opened in the final 16 minutes as Ukraine winger Andriy Yarmolenko converted a penalty after a handball as Magdeburg's defence tired.

Defender Marc Bartra netted a header before Shinji Kagawa added a fifth on 90 minutes