It's Antony effect.
Antony boost his teammates to play good like this, he make Real Betis back to sixth position. They're getting close to reach 4th position, I think it's still realistic. The top 3 positions are unlikely to change.
I just checked Antony recent stats, I can't believe it, I though it was Valverde, but it's Antony!

Anthony hasn’t only elevated Real Betis alone but has given himself more chances to get back to the past Antony everyone was projecting to be the next big thing, seriously I am not surprised by his performance because i have always seen him as a talented player but went to Manchester United when things were not right and plus his transfer fee the pressure was just not easy for him to handle. Manchester United is a bigger club than Real Betis and with less pressure at Real betis he has the ability to showcase his talent like he once did in Ajax.
Real Betis on the other hand are enjoying this success not only because of Antony but also for Isco, the success wasn’t like this before because only Isco was the driving force in the team, now with two or more players the club is winning games and even moving up the rankings which I think will continue with the confidence they currently have.
ona. I understand the kind of team Atletico Madrid is. they're very resilient. They never stop fighting, but so is Barcelona and currently, Barcelona is a better team than they are. In all the 3 games they've played this season, Barcelona have outplayed Atlético in all of them and this won't be any different.
Yes Barcelona are in better shape now than any club in Laliga but I do not rule out Atletico Madrid against anyone because they can turn up anytime against them. This season I think they have faced each other three times and each club has won once and drew the third game, so there is no reason to say one is a clear favorite to win this game. I think this is Atletico only shot to a trophy this season