Probably nobody was expecting such a comeback by Espanyol.

How did Atletico Madrid managed to lose like that?
Atletico's coach is the only one who could answer that question correctly. He changed strategy when his team dominated the game, owned most of possession, also gave so much pressure to the Espanyol. One of the stupidest decision i have ever seen from a manager at his calibre. No doubt his team is always stagnant and never progressed well.
I was also a little surprised to see Atletico Madrid lose to Espanyol, even though they had more possession and had more shooting opportunities. But all of that was for naught when the team ultimately lost, and it was surprising for Atletico Madrid fans, as they faced a team that wasn't particularly strong in La Liga. And this result could be an indication that Atletico Madrid will likely remain like last season, barely managing to finish in the top four without seriously challenging for the title.