|Triumph's Jerry Jefferson missed seven free throws but still managed to lead all scorers with 19 points|
Triumph Lyubertsy blew a 14-point lead but made enough plays at the end to claim a 76-75 win at Mad-Croc Fuenlabrada.
In the opening game of the EuroChallenge Quarter-Final series, Quino Colom had a chance to win the game at the death for the hosts but missed a contested lay-up.
Triumph will attempt to sweep the Spaniards with the second meeting in the best-of-three showdown on Thursday in Moscow Region.
Captain Artem Kuzyakin and Jerry Jefferson had 19 points apiece for Triumph, a team that has been on a roll of late.
Led by coach Vasily Karasev, a former point guard for Russia's national team, Triumph hit back from an 0-3 start in the Last 16 with three straight victories to progress to the final eight.
Despite facing a double-digit deficit, Fuenlabrada dug deep and fought back to move in front in the fourth quarter.
The last time they had the lead came courtesy of a Kirk Penney three-pointer that made it 73-70.
After Jefferson split a pair of free-throws to close the game to 73-71 with 2:59 to go, Kyle Landry connected from long range to put Triumph in front.
Jefferson, who made just seven of 14 free-throws, was then fouled and sank a pair at the line for a three-point advantage.
Colom, the young point guard of Fuenlabrada who recently signed a contract extension, drove into the lane and made a 10-footer with 48 seconds to go to close the gap to one.
Kuzyakin was called for a foul on the shot but Colom missed the free-throw.
With 20 seconds to play, Triumph's Tywain McKee was off target with a jumper and Fuenlabrada rebounded before calling a timeout.
Triumph had fouls to burn but with nine seconds to go, they couldn't afford to commit another or Fuenlabrada would receive free-throws.
Colom dribbled beyond the top of the key and then darted past his man into the lane.
He went up for a left-handed lay-up but the ball stayed out and Triumph celebrated a narrow triumph.
Fuenlabrada were just 12 of 21 at the free-throw line and Triumph also had a bad night, making 16 of 25.
Landry finished with 16 points and 10 rebounds.
Leo Mainoldi led the balanced Fuenlabrada attack with 13 points, while Mike Hall had 11 points and nine rebounds.