Rangers had top spot in their Europa League group ripped from them inside stoppage time after Christian Fassnacht snatched a late winner for Young Boys.
Two errors by James Tavernier cost Steven Gerrard’s side, who led through Alfredo Morelos and had the better chances against the Swiss champions.
First, Tavernier lost possession near his own corner flag in the lead up to Roger Assale’s leveller, then the captain’s slip allowed Fassnacht to burst forward and scud a 93rd-minute winner past Allan McGregor.
Feyenoord’s victory over Porto in Rotterdam means all four teams in Group G now have three points from their opening two games.
Rangers now face a double header against Porto, travelling to face the group favourites in Portugal in three week’s time.
Young Boys have last laugh
For 93 minutes of this contest, it appeared that Rangers had delivered another accomplished performance in keeping with their ongoing development in continental combat. Prior to this defeat, Gerrard had lost just twice in 23 Europa League games and for large swathes in Bern, that experience was evident.
They were defensively unflustered, disciplined in midfield, and sporadically menacing in attack against a side who were only denied a Champions League group stage place by Red Star Belgrade on away goals.
Morelos’ opener was ample reward for an unfussy first-half performance. The Colombian striker had earlier scuffed a tame effort straight at goalkeeper David von Ballmoos after scuttling on to a Borna Barisic pass into the left channel, but he was much more clinical when a near-identical opportunity came again. This time, the 23-year-old barrelled after the ball, bounced Frederik Sorensen aside, and advanced into the box before whipping a clinical finish across Von Ballmoos.
It was his ninth European goal this season and a 13th in 25 Europa League games for a Rangers side who were suddenly in command of an erstwhile even contest. Indeed, they might even have doubled their interval advantage had Sheyi Ojo not slashed an an effort across the face of goal just before the whistle.
Young Boys, who had lost their opener in Porto, had previously gone 24 games unbeaten at the Stade de Suisse and lost just once in 14 this term. It was only to be expected, then, that they would be roused after the interval and it took them just five minutes to restore parity en route to reviving their Group G ambitions.
Tavernier was caught on the ball near his own corner flag and, when Ulisses Garcia flashed a delivery across the face of goal, Assale got in front of Filip Helander and thrust out a leg to divert it into the net.
With Rangers having opted not to take up their ticket allocation in response a second Uefa charge for sectarian singing, only a pocket of their fans had managed to find their way into the ground. They were drowned out by a home support enlivened by the goal, but the change in atmosphere did not unduly affect the visitors.
Indeed, it was Rangers who continued to cleave the better openings. A ferocious Morelos lash from the right apex of the area was unconvincingly shovelled over by Von Ballmoos, then the Colombian might have had a penalty after appearing to be caught by Garcia at the back post. The striker then had one more chance, only to see his fierce deflected effort pushed away by Von Ballmoos.
Still, a point would have been a valuable prize after the opening win over Feyenoord and that looked the most likely outcome as the game neared a conclusion.
However, when a clearing Helander header was redirected back towards the Rangers defence, Tavernier lost his footing as he made to clear, allowing Fassnacht to stride forward and fizz a low strike past Allan McGregor. Within a few seconds, Gerrard’s side had gone from topping the group to wondering what had gone wrong.