Barcelona came from behind to beat Unionistas da Salamanca 3-1 and reach the Copa del Rey quarter-finals.

The third-tier team threatened an upset when Alvaro Gomez’s first-half goal gave them the lead.

However, Ferran Torres levelled in the closing seconds of the first half, before Jules Kounde and Alejandro Balde netted in the space of four second-half minutes to complete the turnaround.

Unionistas were quickly on the front foot at Campo de Futbol Reina Sofia and Mario Losada shot wide in the first minute.

Marc Guiu had a shot blocked for the visitors, 31-time winners of the competition, before bringing a good save out of home goalkeeper Ivan Martinez.

Torres responded with a shot for the visitors on the half hour which fell just wide but Barca were behind five minutes later when Gomez volleyed a cross past goalkeeper Inaki Pena at the back post.

In the first minute of added time at the end of the first half, the visitors levelled when Torres’ shot had too much power for Martinez to keep out.

Defender Pau Cubarsi, 16, replaced Andreas Christensen at half-time for Barca, who also brought on Ilkay Gundogan, Pedri and Robert Lewandowski just past the hour mark as they sought the go-ahead goal.

After Lewandowski had brought a save out of Martinez, they got it when Kounde found the net with a well-struck 25-yard effort.

And in the 73rd minute it was 3-1 in similarly impressive fashion when Spain international Alejandro Balde shot powerfully home from distance.

Frenkie de Jong, playing his 200th game for the club, was on the pitch at the final whistle as Barca saw out the closing stages comfortably to ensure their place in the last eight.