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Diego Simeone's side had done much of the heavy lifting with a 2-0 win at the Camp Nou in the first leg, and that cushion proved just enough to withstand an early Barca blitz as the visitors struck twice in the first half to level the tie.

Lamine Yamal capitalised on a Clement Lenglet error to open the scoring in the fourth minute, finishing neatly past goalkeeper Juan Musso after Ferran Torres set him up.

Torres then made it 2-0 in the 24th, racing clear on to Dani Olmo's pass and driving the ball into the top corner.

Atletico, rocked but not floored, found a lifeline in the 31st minute. Marcos Llorente burst down the right and drilled a low cross to the far post where Lookman outpaced his marker and fired inside the left post to restore the hosts' aggregate lead.

Barcelona dominated possession after the break and had a third goal ruled out for offside against Torres as Pedri and Gavi controlled the midfield.

Barca finished with 10 men after a last-man challenge brought a red card for defender Eric Garcia and Atletico held on to secure a place in the last four against Arsenal or Sporting CP, which  play on Thursday (AEST) with the Premier League leader 1-0 up in the tie.

"We've been dreaming big for a long time," Musso said after the match.

"We wanted to get through this stage and we knew we could do it. We remain true to our dreams. It's a close-knit and lovely group. We deserve great things. The team will give it their all."

Barca silenced a raucous stadium inside four minutes thanks to a schoolboy error from Lenglet, who was deputising in defence with Atletico missing David Hancko and Jose Maria Gimenez through injury and Marc Pubil through suspension.

Lenglet's attempted pass back to Musso lacked conviction, allowing Yamal to pounce. Torres collected the loose ball and slipped a neat return pass into Yamal's stride. The teenager burst into the box before tucking the ball under Musso.

Pushed into further mistakes by Barca's press while trying to play out from the back, Atletico paid the price again.

After another sloppy turnover, Olmo surged through midfield and threaded a precise pass between the centre backs. Torres timed his run to beat the offside trap and hammered a rising strike into the top left corner to level the tie on aggregate.

Barcelona nearly struck a third moments later when Lenglet misjudged another pass, but Musso produced an extraordinary reflex save at point-blank range to deny Fermin Lopez.

Lookman's goal woke the Metropolitano crowd up again and the second half resumed at a calmer tempo.

Barca continued to monopolise possession though and thought they had a third when Torres converted from close range after a Gavi effort deflected into his path, but the video assistant referee (VAR) ruled him offside.

With Olmo, Pedri and Gavi dictating the play in midfield, it appeared only a matter of time before Barcelona struck again but the contest took another twist when substitute Alexander Sorloth was held from behind by Garcia while racing clear on goal.

Referee Clement Turpin initially showed a yellow card but upgraded it to a red after a VAR review, leaving Barcelona down to 10 men in identical fashion to the first leg, when Pau Cubarsi was dismissed for hauling down Giuliano Simeone.

Sensing vulnerability, Atletico pressed for an equaliser on the night, but Sorloth and Nahuel Molina squandered openings.

The final whistle was greeted with relief by the home fans. Beaten on the night, Atletico march on – battered, breathless and back in the last four for the first time in nearly a decade.

"That's football for you – it all comes down to the little details," Barca coach Hansi Flick said.

"We need to improve in certain areas, but in terms of mentality and attitude ... the team gave it their all. That's exactly what we want to see. They did a fantastic job, but we didn't quite make it."