Eighteen-year-old Oliver Torres had a night to remember for Atletico, marking his first competitive start for Atletico by opening the scoring in the first minute.
Diego Costa also got on the scoresheet with his 11th goal of the season, with Gabi's late strike adding an extra shine to what was a fine night all around for Diego Simeone's side.
Atleti are now just one point behind league leaders Barcelona but Betis are in real trouble, slipping into the relegation zone.
Giovani dos Santos scored twice, set up another goal and missed a penalty as promoted Villarreal put local rivals Valencia to the sword in a 4-1 drubbing.
Only Real Madrid have avoided defeat at El Madrigal so far this season and Valencia could not follow suit as Villarreal scored twice in the opening 22 minutes through Ikechukwu Uche and Hernan Perez before Giovani made it 3-0 just after the break.
Valencia gave themselves a glimmer of hope when Ricardo Costa pulled a goal back but Giovani's late second wrapped up a convincing victory for the Yellow Submarine, who move to within two points of third-placed Madrid.
Forward Antoine Griezmann scored twice with his head as Real Sociedad extended the misery for bottom side Almeria by inflicting a fifth consecutive defeat.
The Frenchman doubled his Primera Division tally to four with a goal early in each half to set up a 3-0 result as their Andalusian opponents' winless run since the start of the season was stretched to 10 matches.
On-loan Roma left-back Jose Angel scored only the second goal of his career and the first since his senior debut season for Sporting Gijon in 2009 as Sociedad moved up to ninth in the table.
Goals from Ivan Rakitic and Jairo Samperio handed Sevilla a 2-1 victory over 10-man Osasuna at the Estadio Ramon Sanchez Pizjuan.
The home side stretched their unbeaten run to seven matches as they moved up to 10th in La Liga table while their lowly opponents, who have lost three of their last five, remain second bottom.
Damia Abella was sent off after 35 minutes for Osasuna, while Oriol Riera claimed a late consolation but they were unable to find an equaliser in the closing minutes.