Substitute Ousmane Dembele rescued a late point for Barcelona in an exciting finish against Atletico.
A disappointing game was drifting to a goalless draw when Antoine Griezmann whipped in a corner for Diego Costa to head Atletico ahead in the 77th minute.
The home team looked secure, but Lionel Messi picked out Dembele with a minute left and his controlled finish beat Jan Oblak.
This result leaves Barcelona top of La Liga and Atletico in second.
Billed as a key clash between the top two, the game descended into a niggling midfield affair, with Atletico keen to contain the visitors and play on the break.
Barcelona wanted a response after a surprise 4-3 defeat at home to Real Betis in their last game, but were not allowed to click into gear despite having more than 70% possession.
Messi and Luis Suarez were starved of service and were well marshalled by an Atletico team shorn of first-choice defenders Diego Godin and Jose Gimenez.
Costa’s goal on 77 minutes was actually the game’s first shot on target, the Spanish striker wriggling free at the back post to head in his first ever goal against Barcelona.
A win would have taken Diego Simeone’s side top, but the league leaders had other ideas.
Dembele has struggled for form recently, but he kept his cool in the final seconds to stop Barcelona sliding to a second consecutive defeat and stay top of the table.