Simeone finds the fire and Atletico given hope after throwback win over Liverpool

But for the next 86 minutes of an attritional and intensely absorbing encounter at the Wanda Metropolitano on Tuesday, Atletico's coach was anxiety personified.

A flapping, barking, swaying, scuttling, fist-pumping ball of energy, Simeone's sheer force of will would become a mirror image of his team.

"I'm not sure if Diego saw much of the game because he was animating the crowd so much," said Liverpool coach Jurgen Klopp.

Liverpool remain heavy favourites to overturn Saul Niguez's early finish and a 1-0 deficit at Anfield next month but for Atletico, beating the world's best side -- and the way they beat them -- may have lasting effects beyond who makes it through.

For 90 minutes, Atletico found themselves again with a throwback defensive display that to those outside Spain might feel familiar but, to Atleti's fans, has been all-too absent this season.

In La Liga, they were undone by Barcelona and steamrolled by Real Madrid. In Europe, they were outmanoeuvred by Juventus and outfought by Bayer Leverkusen. In the Copa del Rey, they were embarrassed by Cultural Leonesa.

Yet against Liverpool, after being written off and deemed incapable of keeping the tie alive for the second leg, Atletico were tenacious and committed.

And they looked to their coach, who seemed to have the fire in his belly again.

As Atletico's season has slowly deflated, Simeone has lost some edge too. He appeared defeated in December when calling this a "transition season" and then accepting in January when expressing relief after a goalless draw at home to struggling Leganes.

On the sideline, his hands have not been making orders but planted in his pockets. Some fans have whistled him while others have stayed silent when asked to give more vociferous support. 

But against Liverpool, Simeone was irrepressible. When Saul made a burst down the wing in the second half that earned Atletico a throw-in and some precious extra seconds, Simeone celebrated it like a goal and demanded 60,000 fans did too.

- Inspiration -

When a ball-boy dutifully handed Trent Alexander-Arnold the ball to take an early short corner, Simeone raged, making a grasping gesture down the touchline that said: "Next time, hold on to it tight".

At one point in the first half, Simeone was so far from his technical area and so close to the pitch that when a pass put the ball right next to him, he threw his arms up to insist he would not intercept.

Simeone inspired the fans and was inspired by them.

"In the eight years I've been here I've rarely felt an atmosphere as good as it was tonight," he said.

Before kick-off, flares were thrown as Atletico's bus arrived under plumes of red smoke. "We started to win this game when the team bus turned around the roundabout and we saw our people," said Simeone.

Whether this was a last hurrah for his old Atletico or a sign they can come again remains to be seen.

Written off, and facing the European champions, Atletico rallied against their inferiority. The expectations will be different when they play Villarreal at home in La Liga on Saturday.

After the final whistle blew, Atletico's players stayed out on the pitch, saluting their supporters -- who held up their red and white scarves -- with applause and clenches of fists.

Liverpool defender Andy Robertson said their opponents acted like they had won the tie already but satisfaction was not borne out of complacency.

After a hopeless season, Atletico finally have something to hold onto.