Atletico Madrid with a man down they still resisted until minute 85 but then they were undone by the old one-two of Luis Suarez and Lionel Messi as Barcelona fans were left singing ‘champions, champions’.
Suarez got the first with a long-range low curling shot that went just under the dive of Spain’s toughest to beat goalkeeper Jan Oblak. And just a minute later Ivan Rakitic sent Messi through and he danced around Jose Gimenez and Diego Godin before rolling in the second.
They are the leading scorers in La Liga with 20 and 33 league goals, and they surely now part of the title-winning team. Messi and Suarez have scored two fewer goals than Real Madrid this season.
First came Costa’s costly tantrum. He wanted a foul on 28 minutes and when referee Jesus Gil Manzano did not award it he swore at him and the match official immediately pulled out the red card.
The referee was then swamped by furious Atletico players who could not believe the colour of the card. Costa had delivered the insult with relative calm but he was now incandescent and went nose to nose with Mr Gil.
He had to be dragged back from the referee and Gerard Pique helped usher him off the pitch talking in his ear as he walked.
Referee Gil could be seen explaining to furious Atletico players that Costa had said to him: ‘La puta madre que te pario’ which is a commonly used Spanish swearing phrase that translates: ‘The f***ing mother that gave birth to you’.
Barcelona are now 11 points clear and with only seven games left they can fully turn their attention to the Champions League — Ole Gunnar Solskjaer was watching in the stands; he will have learned nothing he did not already know.