Atlético Madrid conceded a two-goal lead then fought back from two down in a wild 4-4 draw with Barcelona in a Copa del Rey semi-final first leg thriller.

After Diego Simeone's side scored twice in the opening six minutes through Julián Alvarez and Antoine Griezmann, Barca raced through the gears in a high-octane performance.

The superb Pedri Gonzalez pulled one back with Pau Cubarsi, Inigo Martinez and Robert Lewandowski going on to score for the Catalan giants.

Marcos Llorente netted for Atletico before Alexander Sorloth struck in the 93rd minute to leave the tie perfectly poised ahead of the second leg at the Metropolitano stadium on April 2.

"It's a terrible result when you go 4-2 up," Pedri said. "You have to be more careful, these are things we have to learn."

"Today we started badly but I'll focus on how the team reacted," he added. "When we got in front we have to be calmer. The second leg will be difficult, but we will go there to try and win."

Hansi Flick left Barca's top goalscorer Lewandowski out of the starting line-up, with Ferran Torres taking his place in a false nine role.

Simeone picked a strong side despite his side's extremely tricky fixture list, with this the first of three matches against Barca and a Champions League last 16 tie against Real Madrid on the horizon.

Atlético took the lead inside the first minute, with Alvarez pouncing at the back post after Griezmann's cross was flicked on.

Atlético doubled their lead in the sixth minute when Jules Kounde gave the ball away and Alvarez produced a stunning pass to release Griezmann.

The French forward was being pressured by Alejandro Balde but cleverly worked room for a shot, which Wojciech Szczesny got a hand to but could not keep out.

After Atletico's opening salvo, Barcelona dominated the rest of the first half.

Ferran Torres should have levelled for Barcelona after Raphinha sent him through on goal but his shot was week and Atlético goalkeeper Juan Musso saved easily.

The La Liga leaders hit two goals in two minutes to pull back level, with Kounde setting up Pedri for the first before Cubarsi nodded home from a corner.

Torres spurned another golden chance for Barca's third, rounding Musso but misfiring under pressure from Clement Lenglet, on loan from the Catalans at Atlético. (AFP)