As they contemplate how to overturn a 4-1 deficit to reach the Champions League final, nine-times European Cup winners Real Madrid are taking inspiration from a similar feat against Derby County four decades ago.
The Spanish giants were caught cold by Borussia Dortmund in the first leg.
Since their return to Spain, Real have delved into their extensive archives to dig up past examples of heroic fightbacks to convince fans and players of second-leg possibilities.
Real have overturned an identical scoreline once before in Europe's elite club competition, against Derby in 1975.
Charlie George scored a hat-trick for the English champions in a 4-1 second-round triumph at the Baseball Ground, and he scored again in the return leg at the Bernabeu.
However, a Real side which included current Spain boss Vicente del Bosque levelled the tie to force extra time, and striker Santillana struck a 100th-minute decider for a famous 5-1 victory, to progress 6-5 on aggregate.
“The games against Derby and Borussia Moenchengladbach (a similar comeback in the UEFA Cup) were incredible games,” Santillana told sports daily Mar-ca. “The Bernabeu, if you light the match, burns everything."
Real will be wary of launching a cavalry charge at a Dortmund side unbeaten on their travels in Europe this year as it would leave their shaky defence even more exposed than usual.
They have the leakiest backline of the four teams remaining with 18 goals conceded, and have kept only one clean sheet in the competition so far.
The second leg is also a challenge to Real coach Jose Mourinho's prestige as failure to progress from a third successive Champions League semi-final would test the patience of club president Florentino Perez.
With the La Liga title about to fall to Barcelona, and Real's European campaign hanging by a thread, next month's King's Cup final might end up representing Mourinho's last chance for major silverware this season.
Dortmund coach Juergen Klopp will have a full squad to choose from with midfielder Nuri Sahin's Saturday showing possibly earning him a starting spot against the team he joined from Dortmund in 2011.
"People had been saying for weeks there is only one team in Germany that can rotate and still win games," said club CEO Hans-Joachim Watzke, in reference to fellow semi-finalists Bayern Munich, who are 4-0 up going into their second leg against Barcelona on Wednesday.
"I am delighted that it has now worked for us twice in a row and to be able to show people that we have players who can do it.”