Los Blancos had been flying, bossing Barcelona and creating bountiful chances during a dominant opening 45 minutes at the Santiago Bernabeu.
The hosts seemed destined to break the deadlock in a semi-final tie level at one goal apiece after the first leg in Catalunya.
However, Suarez had other ideas, netting two goals, and forcing an other, as he propelled reigning champions Barca into their sixth consecutive Copa final with a 4-1 aggregate win.
That was hard enough for Real fans to take but the manner of his second strike, a Panenka penalty, felt like he was mocking the European champions in their own back yard.
It is Madrid captain Sergio Ramos who usually pulls off that trick from the spot but now, every time he does it, Madrid fans will be forced to remember this humiliation at the hands of Barca's Uruguayan sharpshooter.
He's hurt them before, of course, many times.
Suarez’s double takes him to an astonishing 11 goals in 13 appearances in all competitions against Barcelona’s arch-rivals, making Real his favourite victims. Not even Lionel Messi has netted as many times against Madrid since Suarez arrived at Camp Nou in 2014.
This was also a lesson for Real Madrid’s young gun, Vinicius Junior, who did everything but put the ball in the back of the net.
The first half was actually one of Barcelona’s worst in Ernesto Valverde’s entire reign, which was no mean feat, given this this semi-final second leg represented his 100th game in charge.
Barcelona lacked ideas. In fact, the visitors didn’t seem to have a game plan at all; it was that bad.
Only slack finishing by Real Madrid and great goalkeeping by Marc-Andre ter Stegen kept the score level at the break.
Suarez also looked lethargic. His late goal against Sevilla at the weekend was supposed to have raised his confidence but there was a worryingly familiar look of sluggishness about his play.
Ousmane Dembele was also disappointing in the first half, unable to hit the heights he managed before his ankle injury a few weeks ago.
The Frenchman had been in sensational form but now looks back to square one, with some horrific touches that saw him lose possession far too many times.
That allowed Real's two centre-backs and their midfielders to concentrate solely on marshalling Messi, which they did comfortably.
The one time the Argentine squirmed away from them, Toni Kroos chopped him down – and somehow avoided a booking in the process.
Nothing was going Barcelona’s way, but Madrid weren’t happy either. After all, what good is possession without a goal to show for it?
Vinicius had been sensational, ripping Nelson Semedo and Gerard Pique to shreds, but just could not put the ball in the net.
On several occasions, he had Madrid fans on their feet, but they nearly always ended up with their faces in their hands after poor finishes.
Then, five minutes after the break, with the hosts still well on top, Suarez produced a killer finish from Dembele’s pass to silence the Bernabeu crowd.
It was Barcelona’s first opportunity of the game and Suarez took it. Suddenly reinvigorated, he began to torment the Madrid back four.
He was ready to bundle home the second but Raphael Varane did it for him. Then Casemiro brought down Suarez in the box and he produced his coup de grace, the Panenka.
Suarez may be showing his age, he may go for weeks without a goal these days, but when he gets the scent, he will not let it go, like the cold-blooded killer he is.
Vinicius, who fired off plenty of shots but wildly, could learn much from the Uruguayan.
Indeed, whereas the Brazilian emptied his chamber – taking six pops at goal, more than Barcelona managed as a team – to no avail, Barca’s marksman hit the target once again.
It's why they still call him 'El Pistolero'.