Anke De Mondt buried a three-pointer with seven seconds remaining to lift Halcon Avenida to a 77-74 win over EuroLeague Women newcomers Nadezhda.
Beaten in overtime at home on their debut in the competition last week, Nadezhda had a chance to pull level two seconds from the end but Belarus international Anastasiya Veremeenko missed from behind the arc.
Salamanca club Avenida improved to 1-1 with the Group A triumph.
The winners got 21 points from Le'Coe Louise Willingham while Nadezhda wasted a game-high 25 from Olga Ovcharenko.
A De Mondt jumper had given Avenida a 74-67 lead with 1:22 remaining, only for Shameka de Lynn Christon to spark a 7-0 run with a three-ball and two free throws.
Begona Garcia tied the game at 74-74 with a made jump shot 11 seconds from the end only for De Mondt to steal the headlines with the game-winner.
Christon had 18 points while Veremeenko scored eight and pulled down nine rebounds.