Opting to leave Sturridge on the bench and start 20-year-old Origi was a bold call – but Klopp was not just brought to Liverpool for his witty one liners, he was appointed for his managerial knowhow.
And here it paid off.
After a special rendition of ‘You’ll Never Walk Alone’ was sung by both fans amid a sea of yellow, finally we got to see how Klopp’s side would cope in what had been labelled ‘El Kloppico’.
The hosts had early chances with Henrikh Mkhitaryan and Marco Reus.
Mamadou Sakho then had to pull off a good block from Mkhitaryan as the home side tried to break the Reds open.
The best chance before the opening goal still fell to Liverpool when Dejan Lovren headed a Milner free-kick into the ground and then into the hands of Dortmund keeper Roman Weidenfeller.
Pierre-Emerick Aubameyang then went close with a free-kick as it looked set to be a long night for Klopp on his return.
But suddenly the mood changed when Origi scored and Klopp beat his chest in celebration.