كتب : Sherif Tarek
The Egypt striker was introduced as a second-half substitute, and he doubled the Borussians' lead on 77 minutes after intercepting an awkward pass to go one-on-one with the keeper.
Bulgarian frontman Dimitar Rangelov opened the scoring on 37 minutes.
Zidan missed his team's previous two friendly matches, as he had a brief rest after wrapping up his international duty at the FIFA Confederations Cup.