Darius Hargrove scored the winning basket with one second left in overtime to give CSU Asesoft Ploiesti a thrilling 97-95 win over BC Donetsk.
CSU were led by Arvydas Cepulis' 29 points, Hargrove's 26 and Catalin Burlacu's 20 as they held off the determined Ukrainian club.
This was a wild game that saw both teams go on extended scoring runs before a fourth quarter and overtime in which the lead went back and forth.
Donetsk led 27-19 early in the second quarter only to see CSU turn the game around with a 16-0 run to go on top, 35-27.
The Romanians opened the second half with 10 straight points and eventually pushed their lead to 16 before Donetsk mounted a comeback of their own, going on a 16-2 run to pull within two near the end of the third quarter.
The teams exchanged leads 12 times throughout the fourth quarter and overtime before Hargrove's last-second jump shot ended it.
Marque Perry led Donetsk with 33 points, including 17 of 18 at the free throw line.
Rostyslav Kryvych added 19, hitting four of eight from three-point territory.
Although neither team will advance to the Last 16, both showed their quality in this hotly-contested finale.
The loss capped a disappointing European season for Donetsk, who had an eight-point first-leg lead in their Eurocup Qualifying Round tie with Bilbao, only to fall by 11 in Spain and fail to advance.
In the EuroChallenge, the Ukrainian outfit continued to struggle, with coach Ramunas Butautas eventually getting fired.
The club replaced him with Drazen Anzulovic, who will now attempt to bring success on the domestic front.
Ploiesti will also have to be content with focusing on matters in their own top flight in Romania.