Borussia Dortmund put their domestic troubles to one side to book their place in the knock-out stages of the Champions League with a comfortable 4-1 win over Galatasaray marred by some ugly scenes in the stands.
Three of the goals came in the second half as Galatasaray crumbled. Marco Reus opened the scoring six minutes before the break, but although Hakan Balta pulled one back for Galatasary after Sokratis Papastathopoulos doubled Dortmund's lead, Ciro Immobile's strike and a Semih Kaya own goal confirmed the margin of victory.
The match was twice stopped by officials in the second half due to flares being thrown on to the pitch and set off in the stands, and Jurgen Klopp was screaming for it to be stopped again late on as further firecrackers could be heard around the ground.
Whatever the disturbances off the pitch, Dortmund had little to worry about on it.
While their Bundesliga form remains miserable, this was a fourth win out of four in the Champions League, and it came with relative ease.
They dominated possession early on - even if the best chance fell to Galatasaray's Wesley Schneider with an acrobatic overhead kick - and Papastathopoulos rattled the crossbar with a header in the 25th minute.
Shinji Kagawa then fired just wide after a great run from Henrikh Mkhitaryan, and the breakthrough arrived in the 39th minute when Lukasz Piszczek picked out a defence-splitting run from Reus who slipped the ball home.
Schneider tried to catch Roman Weidenfeller flat-footed at the start of the second half with a half-volley but while he beat the goalkeeper, his shot bounced wide.
Then came the first of the delays with flares thrown on to the sidelines of the pitch where the substitutes had been warming up.
As soon as the game restarted, Dortmund doubled their lead with a short corner routine and a fierce header from Papastathopoulos.
Galatasaray got one back through Balta's near post header in the 69th minute, but before they could entertain any ideas of a comeback, Immobile struck Dortmund's third - making up for a poor first touch as he stretched to slip the ball beyond the goalkeeper when put through on goal.
Aurelien Chedjou denied Pierre-Emerick Aubameyang with a brilliant tackle after the Dortmund man had ridden the goalkeeper's challenge, but the fourth goal arrived in the 85th minute when Kaya inadvertently turned in Immobile's cross.
Another flare in the crowd caused a temporary halt, and by the finish both sides were keen to get off the pitch.