Rangers were reeling from five successive home defeats prior to the arrival of Athletic Bilbao in the first leg of their Europa League quarter-final.
Facing the team sitting fourth in La Liga with one of the continent's hottest properties - Nico Williams - on the wing, many worried about the fragility of the Ibrox back line, missing the suspended John Souttar.
Those concerns intensified following a red card for Robin Propper after just 13 minutes.
Yet, thanks to a defensive masterclass and the heroics of keeper Liam Kelly, who replaced Jack Butland in goal, Barry Ferguson's side kept a clean sheet against all odds.
Rangers will travel to the north of Spain next week with a chance of progressing to the semi-finals against opponents who have now endured three goalless draws in a row.
But how did they do it?
- Dropped Butland still has 'huge part' to play for Rangers - Ferguson
- Late Lyon leveller keeps Man Utd tie in balance after Onana errors
- Tottenham foiled as Frankfurt ride their luck in draw
Ferguson's big call comes off as Kelly stakes claim
Ferguson was furious after his side lost 2-0 to Hibernian at Ibrox on Saturday and suggested changes were afoot.
He was not messing around. Six players were replaced from that showing and the main talking point was the man in between the sticks.
Former England international Butland has been under increasing scrutiny after some high-profile blunders and Ferguson finally swapped his goalkeepers - a decision he called "one of the toughest" he has ever made.
Yet the big call paid off as Kelly, making just his eighth appearance since returning to the club from Motherwell, made a few smart saves before stopping a Alex Berenguer penalty in the second half.
"All the chat before the game was about Liam Kelly and he's done himself so proud," said former Rangers striker Steven Thompson on Sportsound.
"He's a leader. He'll have been feeling massive pressure, but when you get given the chance, you've got to take it and he's done that.
"You can't take him out the team now. That was a heroic performance. Not just the penalty save, his distribution was good, his command of his box was good."
Former Scotland striker Steven Naismith agreed, saying: "Kelly is Rangers' number one now."
'Siege mentality' brings out Rangers' best
The back-four in the loss to Hibs achieved an unwanted feat - conceding two or more goals in six successive league fixtures for the first time since 1894.
It is a long-winded way of saying that Rangers have been leaking goals and have often given themselves a mountain to climb.
It looked like that might happen again after Propper's dismissal.
However, Naismith suggested: "The shock of the red card early on could have changed the dynamic. There's been a siege mentality, us v them, and that's galvanised Rangers.
"They played a narrow 4-4-1, wanting Athletic to play round them. Man for man, everybody is buying in."
Initially lining ...
