The comprehensive victory brings the Catalans to 37 points at the top of the league table, four ahead of second-placed Real Madrid, but with two extra matches played.
Barcelona continued their perfect start in the Champions League and warmed up for the Clasico at the weekend with a 2-1 win over Shakhtar Donetsk on Wednesday
Sergio Ramos has not played against Real Madrid since 2005 but on Saturday, his Sevilla team welcome the Spanish league leaders to the Sanchez-Pizjuan for a reunion.
Barcelona have been eliminated in the opening stage in the past two editions but this hard-fought triumph on the road puts them in a strong position as Group H leaders to avoid a third consecutive strike-out.
Pedri and Ferran Torres' late strikes earned La Liga champions Barcelona a 2-0 win over Cadiz in their first competitive home game away from Camp Nou on Sunday.
Barcelona coach Xavi Hernandez admitted the scoreline flattered his team.
Diego Simeone's Atletico, third, arrived as Spain's most in-form side but Torres stroked home from the edge of the box in the 44th minute to secure victory for Xavi Hernandez's side.
Real Madrid cut intoBarcelona's lead by beating Celta Vigo, but Torres's low first-half finish restored their advantage to 11 points.
Ferran Torres and Stefan Savic had come to blows during the intense Atletico Madrid vs Barcelona clash in La Liga. The match eventually ended 1-0 in favour of the Catalans.
Ferran Torres netted twice and Marco Asensio, Dani Olmo, Gavi, Carlos Soler and Alvaro Morata were also on the scoresheet for the Euro 2020 semi-finalists in an emphatic romp.