Dortmund were fighting for their Champions League lives against Napoli in their Group F matchup, and won 3-1. Meanwhile Schalke were on their travels in Group E, taking on Steaua Bucharest and managing only a draw.
Borussia Dortmund coach Jürgen Klopp warned the critics not to write his side off as they entered a battle for Champions League survival on Wednesday evening.
After losing 3-0 at the weekend to archrivals Bayern Munich - denting the Ruhr side's Bundeliga hopes - Dortmund were desperate to avoid elimination from the continent’s top-level football competition.
Dortmund’s initial worries might have been for their defense, with coach Jürgen Klopp having to replace his back line due to injury. However, at times it looked as though the problem might be at the other end of the pitch, with too many Dortmund chances missed early on.
So, there was relief when a foul by Federico Fernandez - who pulled down Robert Lewandowski - led to a Dortmund penalty. Marco Reus stepped up to calmly take the spot kick, which he slotted away into the bottom right as Pepe Reina dived the other way.
Reus almost scored again some eight minutes later, with a curling free kick that forced Reina into a diving save.
While Dortmund squandered chances, notably from Lewandowski and Mkhitaryan, they might also have easily let Napoli back into the game on at least two occasions.
Jittery moments for home fans
Callejon cracked the ball into the post with half an hour gone, but perhaps Napoli’s best chance of the first half came as Pablo Armero broke forward from left-back just ahead of the break. He lashed the ball at the top corner, but keeper Roman Weidenfeller took no chance, punching away the ball.
The nerves were palpable in the Westfalenstadion, as Napoli threatened to equalize. There was some relief then, when Reus broke down the left and rolled a perfectly weighted ball in front of a central Jakub Blaszczykowski - who fired through Reina's legs to make it 2-0.
The Germans’ nerves were frayed further, when coach Rafa Benitez’ Italians got back into the game 10 minutes later. Gonzalo Higuain picked up a loose pass and gave the ball to Lorenzo Insigne, who fired home with Weidenfeller off his line.
Dortmund, needing a further cushion, got one when Gabonese winger Pierre-Emerick Aubameyang cooly chipped the ball over Reina on 78 minutes, courtesy of an assist by Lewandowsi.
"We very much deserved to win, although Napoli were good opposition," said Dortmund coach Jürgen Klopp. "Our defense played an outstanding game, which was great, but also necessary."
Dortmund and Napoli are now tied in second place in Group F, with Arsenal on top after a 2-0 win against Olympique Marseille.
Snow in place of goals
There was plenty of snow and a temperature of minus 2 in the Romanian capital, where Schalke took on Steaua Bucharest, but the away fans were vocal.
Fans back home perhaps anticipated a win against the hosts - who they comfortably dispatched in Gelsenkirchen - with an early ticket to the last 16 up for grabs for the Royal Blues.
Schalke, without their attacking star Kevin-Prince Boateng, would have felt they should have been ahead by the break, clearly showing the better quality while Steaua struggled for accurate passes.
Stand-in keeper Ralf Fährmann, in for an injured Timo Hildebrand, had little to do in the first half, but did parry a Federico Piovaccari volley on the half-hour.
Despite their greater composure, Schalke themselves did little at the other end to trouble opposition keeper Ciprian Tatarusanu.
There was reason to regret that in the second half, as Steaua - boosted by substitute Fernando Varela - began to test the German defense more frequently. Fährmann was again forced to pull off a useful save 15 minutes after the break, thanks to an effort by Lukas Szukala.
In the end, Schalke were happy to walk back into the dressing room with a goalless draw.
"We let a lot of chances go, but we were lucky in one or two other situations," said Schalke captain Bennedikt Höwedes. "It annoys me a little that we didn't put away the chances."
Although Basel beat Chelsea 1-0 in the other Group E match, the fact that Schalke could only manage a draw meant that the Londoners advance to the group stages. The Germans must now beat a visiting Basel on December 11 to progress to the next stage.