Borussia Dortmund booked their place in the knockout stages of the Champions League, despite suspending star striker Pierre-Emerick Aubameyang ahead of the 1-0 Group F win over Sporting Lisbon.
Gabon international Aubameyang, Dortmund's top-scorer with 10 goals, was dropped from the squad only hours before kick-off and subsequently given a 24-hour ban by the Bundesliga club due to "internal reasons."
He watched from the stands at Westfalenstadion as his replacement Adrian Ramos headed the only goal of the game with 12 minutes played to ensure Thomas Tuchel's side a place in the last 16 with two group games to spare.
Speaking about Aubameyang's omission ahead of the game, head coach Tuchel told Sky Deutschland: "We totally expect there to be a lot of speculation now, but internal means internal."
Despite all the focus being on events off the field, Dortmund began the game positively and were unlucky not to be awarded a penalty inside three minutes when Christian Pulisic cut inside Sebastian Coates and appeared to be brought down by the former Sunderland defender.
Dutch referee Danny Makkelie waved away the appeals but the home crowd did not have to wait long for their side to open the scoring.
Right-back Matthias Ginter curled in a cross from the right and Colombia international Ramos, on his first European appearance of the season, rose above Paulo Oliveira to send a looping header past Sporting goalkeeper Rui Patricio.
Dortmund, who won the reverse fixture 2-1 in Lisbon a fortnight ago, could not sustain the bright beginning though.
Sporting winger Gelson Martins had an excellent opportunity to level the contest just before the half-hour mark but he took too long to get his shot away after being played through by Luc Castaignos and the ball was smothered by Dortmund keeper Roman Burki.
The hosts had offered very little after taking the lead, although they almost added a second 11 minutes shy of half-time following superb interplay by Mario Gotze and Pulisic which culminated in the latter rattling Patricio's crossbar from six yards.
Left-back Raphael Guerreiro then squandered another opportunity to double the advantage when he shot into the side netting after playing a one-two with Ramos in the final minute of the opening period.
Sporting were much the better team after the break and the lively Martins brought another stop out of Burki within minutes of the restart.
Substitute Adrien Silva was the next to go close for the visitors, flashing a free kick over the crossbar before firing over from distance minutes later.
Tuchel was visibly frustrated with the second-half performance of his players and he was forced to endure a tense final 20 minutes as Sporting continued to threaten.
Former Fulham forward Bryan Ruiz had the best chance to earn the away side a share of spoils but his powerful header from Ezequiel Schelotto's right-wing centre flew narrowly too high as Dortmund held on for a slender victory on a testing evening.