Atlético Madrid win
Since February, Betis has been noticeably weak in terms of results: only 4 wins in 10 matches, defeats to Celta and a draw with Villarreal in the championship, as well as relegation from United in the Europa League. Atlético, on the other hand, is looking very strong: they have won 5 out of their last 6 matches and only lost points in the derby against Real Madrid, where they even managed to take the lead in the minority.
Atlético have yet to secure a place in the Champions League for next season and the mattress toppers still have a spectral chance of competing for second place with Real Madrid.
Historically, Betis have been quite a comfortable opponent for Atlético Madrid: Madrid have won 10 of their last 11 home friendlies, the last time being a loss in 2011. Therefore, I would take a closer look at the victory of the Simeone guys: they have tournament motivation, personal history and current form on their side.