Sam Van Rossom made a two-pointer, with 3.4 seconds remaining, and Valencia beat Crvena Zvezda (81-82) to advance to the playoffs.
It was a late thriller in Belgrade, as the Serbians came close to a big victory at home, thanks to Joe Ragland’s two-pointer, with 15 seconds to go (81-80).
The hosts had come back from a six and seven-point deficit in the third quarter (48-55, 58-64), yet Van Rossom and the visitors stood tall and beat their opponents to clinch a playoff spot.
Bojan Dubljevic had 24 points and eight rebounds for the winners, with Will Thomas adding 11 points.
Stratos Perperoglou posted a game-high 26 points for the losing squad, as three more players scored in double figures.
Valencia remained undefeated in the Top 16 (4-0), whereas Crvena Zvezda dropped to 1-3.
In the other matches, Andorra (4-0) defeated Zenit St Petersburg (1-3) (86-74) and advanced to the playoffs, Unics Kazan (3-1) dominated Cedevita (0-4) on the road (83-100), Unicaja Malaga (3-1) survived Limoges (0-4) (77-78) and Lokomotiv Kuban (3-1) rallied past Ratiopharm Ulm (1-3) to reach the quarter-finals (88-76).