Pedro scored twice as Barcelona came from behind to establish a three-goal lead in the first leg of their Copa del Rey last-32 clash at Cartagena tonight.

The Catalan giants were without injured trio Lionel Messi, Xavi and Daniel Alves, and also rested several other star names for their trip to the third-tier outfit.

Their much-changed lineup was shocked on 17 minutes when Cartagena striker Fernando Rodriguez gave the less-fancied minnows an unlikely advantage by slotting home following Miguel Angel Riau's pass.

However, they could not hang on to their advantage until the break as Pedro and then Cesc Fabregas both scored within the space of seven minutes to put the La Liga champions 2-1 ahead at half time.

Pedro, who has been a substitute in eight of his nineteen appearances this season, then scored his second of the game and ninth of the campaign on 76 minutes to become the club's top scorer this term.

Barca increased what is surely to now be an irretrievable lead for Cartagena by netting a fourth on 88 minutes, as 18-year-old Cameroonian Jean-Marie Dongou opened his account for the club's first team.