- Ángel Correa (86')
Diego Simeone's side are in third place on 54 points, six ahead of Real Sociedad and five behind Real Madrid, close to securing Champions League football next season. Betis are fifth on 45 points. Betis are fifth on 45 points.
Correa came off the bench and scored the winner five minutes from time with a brilliant run, leaving several defenders in his wake, to shoot from the middle of the box into the bottom left corner for his sixth league goal of the season.
"I'm happy for the goal and for helping the team to get the win," Correa told DAZN. "[The goal] was a bit of watching, reading what the defence was going to do, I guessed and then I cut back and kicked because I was already in the box.
"We come from several wins in a row. The team is working very well and we hope to continue like this until the end."
Atletico had being the dominant side from the start of the match, but until the Argentina international's goal, all their attacking attempts were frustrated by a solid Betis defence and goalkeeper Rui Silva, who recorded six saves.
"When you face opponents who work well defensively like Betis, Angel is one of the best we have in his role," Simeone told a news conference." He's always there, he's always involved.
"It makes me happy [the team's form] and to see the fans that the only thing they come to see is a team that has a heart. Players have done a job for the fans to leave happy."
Atletico face Rayo Vallecano on Sunday, while Betis host relegation-threatened Cadiz.
- Juan Martínez Munuera