Real Betis piled more pressure on Gennaro Gattuso as AC Milan surrendered top spot in Group F in a listless 2-1 home loss in the Europa League.
Giovani Lo Celso set up Antonio Sanabria's 30th-minute opener and curled in a wonderful sealer 10 minutes after the interval to fire the LaLiga side ahead of their hosts, who are now only two points clear of third-placed Olympiacos.
It was no worse a fate than Milan deserved for waiting until the 83rd minute to issue any kind of riposte to their weekend defeat to city rivals Inter.
Samu Castillejo teed up Patrick Cutrone to reduce the deficit and the winger was unfortunate not to win a penalty late on, his frustration boiling over in a late lunge on Lo Celso that earned a straight red card.