Rangers’ Europa League match with Legia Warsaw was stopped after smoke covered the pitch when flares were lit by the visiting fans.
Slovenian referee Slavko Vincic called a halt to proceedings after 75 minutes and led the players from the pitch.
Play resumed five minutes later before Alfredo Morelos scored the winner in the 90th minute to make it 1-0 to Rangers.
Legia Warsaw manager Aleksandar Vuković said he wasn’t surprised by the behaviour of his fans.
He said: “I’m used to seeing this every week and in every stadium in Poland. I know for here it’s a little bit surprising but that’s what we’re used to seeing from fans.
“I’m not somebody who says ‘bravo’ to this kind of behaviour but this is how it is in Poland.”
The atmosphere in the stadium was highly charged despite Rangers having been ordered to close a section by UEFA for sectarian chanting in a previous qualifier.
Legia fans unfurled a huge banner depicting Pope John Paul II before kick-off and former Celtic goalkeeper Artur Boruc was pictured leading the visiting fans in song.