Costa watch Atletico defeat Sevilla 2-0
Costa is set to rejoin Atletico from Chelsea in January, subject to personal terms and a medical, after the clubs agreed a fee for the Spain forward.
Atleti – at their new Wanda Metropolitano home – are doing fine without him for now and led when Yannick Carrasco rounded the keeper.
Antoine Griezmann smashed home their second from close range.
Atletico, who move above Sevilla into second, are one point behind Barcelona, who visit Girona at 19:45 BST.