Before Arsenal arrived at the Bernabeu Stadium on February 21, 2006, no English side had beaten Real Madrid on their own patch. Arsène Wenger's young side overcame a crippling injury list to change all that.
A virtuoso goal from Thierry Henry two minutes after the interval was enough to secure a famous victory. But this was no smash-and-grab raid by an English outfit counter-attacking on the continent. Arsenal could and should have won by more.
With eight players injured, mostly defenders, Mathieu Flamini continued to fill in at left back. There was little option but, like every one of his team-mates, the relocated French midfielder was magnificent.
Arsenal may have had the lead after only 80 seconds when Iker Casillas saved from Jose Antonio Reyes. Freddie Ljungberg and Henry also went close in a first half which the visitors largely controlled. At half time it was so far, so good; then, two minutes after the restart, it got much, much better.
Cesc Fabregas fed Henry in the centre circle and the striker held off Ronaldo and skipped past Alvaro Mejia and Guti before racing into the area and muscling past Sergio Ramos. He planted an angled shot past Casillas and into the far corner of the net. It was stunning even by Henry's high standards.
The 28-year-old celebrated his 34th Arsenal goal in the Champions League by running towards to the 3,500-strong visiting support with his arms out wide.
Madrid tried to respond but Arsenal's back four, superbly marshalled by Kolo Toure, held firm. Indeed, the visitors had their chances to secure a more emphatic win.
In the build-up to the game Wenger had overused the word 'belief'. That and defensive stability, he argued, would be fundamental to his side's chances against a Madrid side packed with stellar talents like Zinedine Zidane, Raul and Ronaldo. In the end, they displayed both qualities in abundance.
Those qualities were on show once more 15 days later as a 0-0 draw in the second leg at Highbury was sufficient to take Arsenal into the last eight of the Champions League. The Final beckoned.