Wisla Can-Pack scored 21 consecutive points over a six-minute stretch of the second quarter on their way to a 75-45 blowout of Besiktas on Wednesday.
Turkish giants Besiktas never recovered.
Holdsclaw had 17 points and eight rebounds for Wisla, who improved to 3-1 in Group A while Besiktas fell to 1-3.
Ewelina Kobryn also excelled for the winners with 14 points, including six in the second quarter, and six rebounds.
Four players reached double figures in points for the Poles.
Aziz Akkaya's Besiktas endured a nightmare night shooting the ball, making only 19 of 60 shots from the floor, including two of 10 from behind the arc.
They also turned the ball over 20 times while Wisla only had 12 turnovers.
Fernandez and Kobryn each had four steals for Wisla.
Laura Harper scored a game-high 26 points in defeat.
Wojciech Downar-Zapolski (Wisla Can-Pack head coach):
"I'm very happy that we won this game. I would like to thank my team for the very good job. We really needed this win and I hope that in the next EuroLeague games we will play as well as we did tonight."
Aziz Akkaya (Besiktas Cola Turka head coach):
"I would like to appologize for our poor game - our only excuse is that we played without two of our most important players. Congratulations to the Polish team for a very good game."