A late goal from Real Betis condemned Nottingham Forest to defeat in their second pre-season friendly match in Spain.
The Reds put in a disciplined and organised display to hold their La Liga opponents who are set for European football this season, but a Ryad Boudebouz strike five minutes from time settled the match at the Estadio Nuevo Mirador.
Betis had the majority of the early play but it took a last-ditch challenge from a defender to prevent Diogo Gonçalves from racing through on goal on 11 minutes.
The Reds looked solid defensively as Betis found it tough to find a way through, while Gonçalves and Matty Cash were having some joy on the wings.
On 30 minutes, Daryl Murphy was unlucky not to find a half-yard of space to get a shot away as he controlled Tendayi Darikwa's cross but a Betis defender got a toe in to clear after the Irishman muscled his way past two challenges.
Forest came out in the second half and Murphy could have put them in front on 53 as he met Gonçalves's cross with a good header but the Betis keeper got his body behind the ball.
Karanka's men were turning the screw and another save, this time a fingertip one, kept out Adlene Guedioura's low shot just before the hour.
Hillal Soudani was introduced from the substitutes' bench in one of four changes and he had two half chances on 71 which were blocked, before the Algerian international then saw an effort chalked off for offside as he made his bow in a Red shirt.
As the game entered the closing stages, Betis came forward as they went in search of the opener and it took a smart save from Jordan Smith to deny them on 80.
But three minutes later they found the breakthrough as Smith did well to tip Cristian Tello's effort onto the post and Boudebouz was on hand to lash home the rebound and give Betis the win.
Forest: Kapino (Smith 46'), Darikwa (Gabriel 86'), Robinson (Osborn 78'), Fox (Lam 86'), Dawson (c) (Ahmedhodzic 86'), Yates (Bridcutt 78'), Cash (Carvalho 66'), Guedioura (Watson 78'), Murphy (Soudani 66'), Lolley (Grabban 66'), Gonçalves (Dias 66')