Barcelona knew what will happen if they allow Atletico Madrid get all 3pt and it would have been game over because the 3 teams won't want to lose and drop point while hoping for others to make that mistake. I don't think the champions league game they lost to Madrid was the cause of what killed Atletico Madrid's morale, they were over confidence after leading by 2 goals against Barcelona and that's bad if you're playing against Barcelona who are also fighting to get that top spot and secure the 3pt, you go all out to give your best and also defend more too, they should have continue to press and defending just like they did to Bayer Leverkusen but they failed. Barcelona will continue their good form till the last day, for now the whole thing is in the hands of the top 3 teams.
This is a successful revenge mission because previously Atletico Madrid managed to defeat Barcelona and now Barcelona did the same thing at Atletico Madrid's home ground.
This is not because they underestimated or were complacent when Atletico Madrid was already 2 goals ahead, but Atletico Madrid did not show good performance and even had a very bad mentality when Barcelona continued to launch attacks, Atletico Madrid players seemed not to know what to do so Barcelona could take advantage of that and score 4 goals to turn things around.
Now it's all over for Atletico Madrid, I think they can no longer enter the competition for the La Liga title this season, from a series of bad results they have received now such as being eliminated from the Champion League and losing 2 times in a row in La Liga, of course it will make the mentality of Atletico Madrid players even worse now.
I won't say they don't know what to do talking about Atletico Madrid because they had everything under control but they couldn't keep the joy in them together, to them the game is done and dusted that the Barcelona side can't come back, at some point I thought it will happen that way but it seems Barcelona are aware of the mistakes they made some months ago how they threw away better opportunities away so it is now or never. I don't think any of the 3 clubs are out of the race even the Atletico Madrid are fully in the race so you can't write them off that easy, Madrid have a chance of dropping point if care is not taken that's why I pick Barcelona ahead of the other 2 teams (Real Madrid and Atletico Madrid).