Thomas Tuchel made four changes to his side that narrowly defeated Hannover 96 at the weekend, with Neven Subotić, Matze Ginter and Gonzalo Castro making way for Sokratis Papastathopoulos, Julian Weigl and Pierre-Emerick Aubameyang. Most notably, however, there was a surprise return for Nuri Şahin who replaced the ill and in-form İlkay Gündoğan.
Despite sitting third in the Primeira Liga, behind the other two Portuguese giants, Porto manager, Jose Peseiro remained focused on the Europa League fielding a strong side. Iker Casillas was handed his competition debut.
Following the encouraging choreography from the Yellow Wall, the match began and to say the start was lively within the first few minutes of kick-off would be an understatement. Porto committed numbers in defence, no doubt to cover their makeshift defence line. It was almost caught out straight away with Mats Hummels showing off his playmaking threat by finding Marcel Schmelzer sprinting in behind the opposition's backline, before having his far-post cross cleared by the covering Martins Indi.
Soon after, Dortmund flexed their attacking muscles with Shinji Kagawa running down the right wing, before winning a corner. Then, Porto's weak defence just switched off. The home side pulled off a nicely-worked short corner to find an onside Lukasz Piszczek, in plenty of space, who needed a second bite at the cherry to beat Casillas and give his side a very early lead.
Not long after the half-hour mark, an integral build-up lead to another chance for Dortmund. Marco Reus cutting in from the left wing and finding Kagawa on the edge of the box, who ought to have done better as he fired wide.
Throughout the first half, Porto's toothless advances were easily repulsed and, as a result, Dortmund managed to control the tempo of the game, often with Hummels pulling the strings.
By contrast, the start to the second half was fairly lacklustre. Both sides venturing into each other's half, to no avail. The Portuguese side, at least, were growing into the match, albeit very slowly. Unsurprisingly, Dortmund surged forward down the wing, yet again, with substitute Moritz Leitner neatly chipping a pass in the box for Kagawa to miss-hit and Reus volleying wide.
However, die Schwarzgelbe's persistence and patience eventually paid off. A seemingly tired Porto defence couldn't keep up with the fast passing as Kagawa found Mkhitaryan who, in turn, cut it back for Reus to slot home the second goal, with the aid of a deflection, rendering Casillas helpless.
Porto's forwards showed some signs of life, but any time they reached the final third, they neither had the creativity nor numbers to threaten a resolute Dortmund defence. It seemed as if the Portuguese giants were settling to cut their losses, which did little to slow down the home side. Kagawa tested Casillas and, minutes later, Mkhitaryan almost made it three by meeting a loopy cross with a strong header that struck the upright.
Borussia Dortmund had won every game this season in which they scored first and Porto nearly threatened to upset that with a late surge, but Dortmund came away with a clean sheet thanks to the goalkeeping heroics of Roman Bürki who was called upon to expertly deny Hyun-Jun Suk.
Borussia Dortmund's quick passing carved Porto open on many occasions, and the scoreline could've been bigger, had the finishing been more clinical, but it was a solid performance, nonetheless.