Dortmund - Borussia Dortmund have brushed off their nightmare Bundesliga form to maintain their perfect Champions League record and book their place in the knock-out phase with Tuesday's 4-1 rout of Galatasaray.
Dortmund are second from bottom of the league following the worst start to a season in the club's history after five straight defeats, but are one of the first teams into the last 16 in Europe.
Borussia remain top of Group D with four wins and posted another heavy win over Cesare Prandelli's Galatasaray having won 4-0 in Istanbul a fortnight ago.
Bizarrely, Dortmund have now picked up nearly double the points, 12, in their four Champions League matches than the seven they have from their 10 league matches.
The game was held up twice in the second-half by crowd trouble as Galatasaray fans threw fireworks on to the pitch, then set off a flare in the stands in the closing few minutes.
Goals either side of half-time from Germany midfielder Marco Reus and Greece defender Sokratis put 2013 Champions League finalists Dortmund into the knock-out phase.
Galatasaray's Berlin-born defender Hakan Balta pulled one back for the visitors midway through the second-half before the hosts scored twice more to put the result beyond doubt.
Italy striker Ciro Immobile netted Dortmund's third just three minutes and 26 seconds after coming off the bench to calm the hosts' nerves after a period of sustained Galatasaray pressure.
Immobile then compounded Galatasaray's misery when his cross was deflected into the back of the Turkish giants' net by defender Semih Kaya.
Dortmund have shown two distinctly different faces this season as another impressive display in Europe again bore little resemblance to their woeful league form.
Marco Reus put Dortmund ahead when right-back Lukasz Piszczek spotted the Germany winger's run and put in a brilliant through-ball.
Reus needed no second invitation to get behind the Galatasaray defence and put his side ahead on 39 minutes.
Dortmund doubled their lead when veteran midfielder Sebastian Kehl rose highest to a corner and headed down for Greek centre-back Sokratis Papastathopoulos -- Sokratis for short.
The 26-year-old scored his first Champions League goal with a half-volley from inside the six-yard box on 56 minutes.
Balta put Galatasaray back in the match with a thumping header at the near post after a Wesley Sneijder corner on 70 minutes.
But Reus made way for Immobile in a decisive substitution as the Italian claimed his third Champions League goal in three games.
Galatasaray's brief period of pressure came to nothing as Immobile finished off a flowing move by Henrikh Mkhitaryan and Pierre-Emerick Aubameyang.
The Italian got the ball in the net despite being fouled by Galatasaray goalkeeper Fernando Muslera on 74 minutes.
Aubameyang then squandered two chances to add to the goal tally before Immobile struck again.
Kaya could only watch in horror as Immobile's pass clipped his boot and span into his own net on 85 minutes.
The result leaves Galatasaray bottom of the table with one point.