Mantas Ruikis drained a last-second three-pointer to secure BC Siauliai their first Group D win, 86-83, and dent BCM Gravelines' hopes of reaching Round II of the EuroCup.
Successive free throws by Paccelis Morlende had brought BCM level at 83-83 with two seconds remaining, but the Lithuanian side had enough time to launch one more attack.
Tadas Klimavicius missed his jumper, but Arturas Masiulis grabbed the rebound and set up Ruikis for his match-winning coup de grace from downtown.
The 21-year-old forward (12 points) was one of four Siauliai players to claim double-figure hauls on the night.
Guard Darius Pakamanis had a game-high 20 points, along with four rebounds and three assists, and he was helped by Arvydas Cepulis (18 points) and Klimavicius, who added a superb 15 rebounds to his 17 points.
Siauliai lost their first three games of the group to ruin their chances of progression and remain bottom, even with this victory.
It was a rather bittersweet night for Gravelines, whose top scorer was Lithuanian guard Dainius Adomaitis (16 points).
The losing point sees them go top by one, but rivals Akasvayu Girona and Maccabi Rishon Le Zion now have games in hand and are favourites to advance.