Chris Singleton inspired a final-quarter fightback as Lokomotiv Kuban beat Barcelona 81-67 to reach the Euroleague Final Four for the first time at the expense of the two-time champions.
Barca looked set for victory in game five on Tuesday, but Lokomotiv turned it around in the play-off decider in their own backyard to become the fourth and final team to qualify for Berlin next month.
Malcolm Delaney led Lokomotiv with 17 points and Ryan Broekhoff weighed in with 14, but it was Singleton who took centre stage in a tense final set to finish with 16 points and 12 rebounds.
Lokomotiv led 26-21 after the first quarter and stretched their advantage to 50-39 at half-time with Delaney coming to the fore and sinking a three-pointer just before the break.
Juan Carlos Navarro and Ante Tomic rose to the occasion as the Catalans stunned Lokomotiv by outscoring them by 23 points to eight to lead 62-58 at the end of the third quarter.
But Lokomotiv were not finished yet and American forward Singleton scored 11 straight points and rattled Barca, who lost their cutting edge when it mattered to miss out on a place in the Final Four.
Stratos Perperoglou top scored with 13 points for Xavi Pascual's men, with 12 from Navarro in a losing cause as their Euroleague campaign came to an end, with Lokomotiv entering uncharted territory by sealing a 3-2 series victory after being 2-1 down.