However, Gers hope they will be toasting progression to the Europa League last eight after next week's second leg at Ibrox.

Helander's tap-in preserved their 12-game unbeaten run against continental opposition and set them up with a golden chance to march on again, while they were also thankful for a stunning late save from Allan McGregor.

Rangers started like a team who could still taste what they had drunk at the weekend – which judging by the videos leaked from the Ibrox dressing room over the weekend was plenty.

Slavia, though, were in no mood to show sympathy. With Gerrard's team far too passive, it took the Czechs just seven minutes to take advantage.

Lukas Provod's cross-field pass found Peter Olayinka out wide, who was allowed to roll the ball back to Stanciu on the corner of the box as Nathan Patterson failed to get tight. Connor Goldson also stood off while Ianis Hagi arrived too late to stop his fellow Romanian sweeping an unstoppable strike past McGregor from 20 yards out.

The Light Blues were looking green around the gills.

Goldson and Glen Kamara were both caught in possession, Joe Aribo was late into a challenge, while Ryan Kent put the ball straight out of the park.

Helander and McGregor almost got in a mix-up too as Jan Kuchta put them under pressure, and it became abundantly clear Slavia – who just like Gers have yet to suffer a domestic league defeat this term and who dumped Leicester out of Europe last month – would not be as generous as previous opponents Royal Antwerp.

However, slowly the colour returned to Rangers' cheeks.

They still had to ride their luck. Provod slid in Kuchta but his shot bobbled wide, while McGregor had to remain alert as Provod tried to whip a sneaky wide free-kick into the near post.

Rangers needed a break of the ball to go their way – and they got one off Goldson's knee nine minutes before the break.

Alfredo Morelos' won his team the chance to send the big men forward but it appeared it was for nothing as Borna Barisic's deep free-kick bounced off Goldson.

Slavia stopper Ondrej Kolar paused assuming it was running out. But it was a fatal mistake as Hagi refused to give the opportunity up and raced to the by-line to hook it back for Helander to tap home.

The half-time break offered Gerrard's team a welcome breather and the chance to regroup.

And Aribo soon caught a second wind. He fired wide with one chance but his dancing feet were note perfect as he skipped into the box before cutting back for Kent, whose shot fired into the turf and was then clawed away by the scrambling Kolar before it dropped under his crossbar.

And Prague were relieved again on 68 minutes as Goldson failed to get a clean connection on another teasing Barisic delivery when a firm header would surely have put Rangers ahead.

Aribo again was the man playing the champagne stuff as he jinked beautifully into the box. But instead of taking the strike himself, the move went flat as he failed to pick out Morelos at the back post.

Patterson was put through another stiff test of his abilities but the 19-year-old stood up to the test with a vital late block, while a breathtaking save from McGregor denied Lukas Masopust to ensure Rangers' quarter-finals dreams remain intact ahead of next week's Glasgow return.