BARCELONA - Atletico Madrid clawed back from two goals down to rescue a last-gasp 4-4 draw at Barcelona in a rip-roaring battle in the first leg of their Copa del Rey semifinal on Tuesday.

Atletico stunned the home side early on, taking a two-goal lead with Julian Alvarez opening the scoring inside the first minute and Antoine Griezmann extending their advantage five minutes later.

However, Barcelona fought back with goals by Pedri in the 19th minute and Pau Cubarsi in the 21st, before taking the lead through Inigo Martinez's header from a corner in the 41st minute.

Barca took control of proceedings and Robert Lewandowski made it 4-2 with a tap-in from close range after great individual work by Lamine Yamal in the 74th minute.

But if Barca's fans were confident of taking a two-goal advantage into the second leg, Atletico had other ideas.

They struck back through Marcos Llorente in the 84th minute and another goal on the counter by Alexander Sorloth in the third minute of stoppage time left it all square ahead of the return encounter in the Spanish capital on April 2.

"That was just crazy," Atletico forward Alvarez told Spanish TV station Movistar Plus.

"We knew it was not going to be an easy game because we were playing against one of the best teams in Europe. We left with the sensation that we did a great job but there are still 90 minutes left where it's still very close.

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"We were winning by two goals but conceded several goals from set pieces and with the 4-2 scoreline it was just a matter of holding on and trying to reduce the deficit for the second leg.

"That's the mentality, always stay in the game. Always keep our heads up, believe that we can do it. That's how we work and you can see that on the pitch."

Barca were caught by surprise when Griezmann crossed for Alvarez to score the opener with a close-range volley 55 seconds after kickoff.

The Argentinian forward then returned the favor in the sixth minute, curling a pass through to Griezmann, who beat the offside trap on a quick counter and extended Atletico's lead.

Barcelona woke up and went on the attack, hitting Atletico with a two-punch combination to level the scores with two goals in two minutes.

Pedri delivered the first blow from inside the box in the 19th minute after Yamal worked his magic to play a brilliant pass to Jules Kounde inside the box, who delivered the assist with a low cross to the middle.

In the 21st minute, Raphinha lofted a cross to the far post where defender Cubarsi jumped higher than Pablo Barrios to head in the equalizer.

Barcelona turned the game around in the 41st minute, with Raphinha's corner from the right finding Martinez unmarked at the far post to head the ball in.

The home side came out strongly after the break but Atletico held on, with keeper Juan Musso producing a brilliant performance between the posts to keep them in the game.

But there was nothing he could do in the 74th minute when Yamal made another outstanding run inside the box before putting the ball on a plate for Lewandowski to tap in to the empty net.

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But Barca's aggressive, and extremely high defensive line proved once again to be a liability as they were hurt by two deadly counter-attacks within nine minutes that allowed Atletico to level the score.