With Jadon Sancho suspended, Borussia Dortmund turned to captain Marco Reus to end a run of three consecutive Bundesliga draws. Once again, the video assistant referee also caused controversy.
The tension was palpable. Borussia Dortmund had been in this position multiple times in recent weeks, approaching full-time with one-goal leads that they had ultimately failed to defend.
Eintracht Frankfurt, Werder Bremen and SC Freiburg all managed to break through and deny the Black and Yellows three points, consigning them to three consecutive 2-2 draws which saw them go into this Saturday's game in ninth place. And now, league leaders Borussia Mönchengladbach were also pushing hard for an equalizer.
When Mats Hummels slid into the back of Patrick Herrmann in the six-yard box, it looked like they would have their chance from the spot — but referee Sascha Stegemann waved play on. The visitors' bench was up in arms — and rightly so; the Dortmund defender had played the leg, not the ball.
"Sorry, but that's a clear penalty," said Gladbach head coach Marco Rose. "Yes, that's clear," his Dortmund counterpart Lucien Favre agreed. "It's a shame the video assistant didn't intervene," added Gladbach midfielder Christoph Kramer.
But there was no call from Cologne and Dortmund held on for a 1-0 win on an evening that could have been much less tense for the home team were it not for an earlier decision in which the video assistant referee did intervene — and decisively.
Just after the half-hour mark, Thorgan Hazard, playing in place of Jadon Sancho after the English teenager was suspended for returning late from international duty, drove determinedly towards goal and unleashed a shot so ferocious that Yann Sommer could only help it on its way into the net.
It was his first goal for Dortmund, and it had come against his former club — or at least it would have been had Marco Reus' retreating heel not been one millimeter offside three passes earlier in the build-up. Not that any of the Gladbach players had noticed the indiscretion, nor the coaching staff, nor any of the 81,300 fans inside a sold-out Westfalenstadion.
But the video assistant with his calibrated lines in a cellar in Cologne had noticed, and rules are rules. The familiar chants of "You're destroying our sport" — and other less polite messages — for the German Football Association (DFB) echoed around the ground and came from both sets of supporters.
Their matchday experience, to which they actively contribute by audibly and visibly supporting their teams, had been damaged once again. But the DFB will insist that the correct decision was reached and, as we all know, one hundred percent perfection in football is what really matters.
Back on the pitch, both sides canceled each other out for large periods, operating in different formations – Dortmund in Favre's favored 4-3-3 and Gladbach in a 4-2-3-1 – but both aggressively pressing.
Both sides were effective in winning the ball but failed to transition successfully, Breel Embolo too often isolated upfront for the visitors while Dortmund were operating without a recognized striker in the absence of the injured Paco Alcacer.
When chances were created, both teams could also fall back on Swiss goalkeepers, Dortmund's Roman Bürki saving from Konrad Laimer and Embolo and Gadbach's Sommer parrying Hummels' header.
But there was nothing Sommer could do about Reus' winner, the Dortmund captain making no mistake after being fed through by Hazard.
"We're happy that we've finally come away with a victory," commented Reus. "We have some tough fixtures ahead of us so today has pointed us in the right direction."
That tough run of games begins with Inter Milan away in the Champions League this week before a trip to Gelsenkirchen to face archrivals Schalke next Saturday, something which hadn't slipped the minds of the massed ranks on the Yellow Wall.
"We want a derby victory!" they roared after their team had successfully run down the six minutes of injury time. By that time, of course, Schalke themselves could be top of the league. Dortmund would take another one-goal win there, no matter how great the tension.