This Europa League first time ever meeting would likely have been a better final than semi-final but the Gunners will fancy having the opportunity to take down Diego Simeone's sides at home before the trip out to Spain next week.
Cristian Tello hit the post for Betis, while Saul struck the crossbar for second-placed Atletico.
Saul Niguez himself tested the woodwork, crashing a fine curling effort against the crossbar, but it was to be the closest they came to a victor as even the injection of Griezmann failed to stir sustained pressure.
"He will be [available] for sure in the return leg, but I think he has no chance to be [fit] for the first leg game".
Now we just have to wait and see if Arsenal listen to Neville or not.
Munir headed the visitors into a 51st-minute lead and then added a second with 17 minutes remaining to end his side's fears of being dragged into a relegation fight and push the hosts through the trapdoor.
Four European giants are apparently looking to strengthen their goalkeeping department next season, with reports suggesting they are eyeing a shot-stopper who is now valued at €100 million (R1.49 billion). "We went down in the worst way possible", said Jemez.
"Further to assessments and scans on Sunday and Monday, we can confirm that Mo Elneny has sustained ligament damage to his left ankle", the English club announced on Monday.
Alaves' triumph confirms their safety, sitting 13th with 41 points from 34 games.
Malaga beat Real Sociedad 2-0 and Espanyol won 2-0 at Girona to damage their Catalan rivals' dreams of finishing in a Europa League spot.
Las Palmas have gone 12 matches without a victory and this makes up their fifth straight defeat.
The result left Girona ninth and Espanyol 16th in the standings, 11 points clear of the relegation zone.