US Valenciennes won 73-65 over Kosit 2013 on Wednesday to improve to 4-5 in Group C.
Nicole Ohlde had 16 points and 14 rebounds to fire the French giants to victory and drop their Slovakian opponents to 3-6 .
USVO trailed 58-51 at the end of the third quarter but outscored their opponents 22-7 over the final 10 minutes for a stunning victory.
A lay-up by Italy international Francesca Zara put them in front for good at 65-63 with 3:11 remaining.
It also accounted for the ninth and 10th points of a 15-0 run that doomed the visitors.
Kosit never revovered and now go into the final week in fourth place.
Janel McCarville had 20 points and nine rebounds in a losing cause.
Hervé Coudray, the USVO coach said after: "We are very happy tonight and I am proud of my team.
"When we are Valenciennes, we don't just want the eighth-finals, we want more.
"We made a very good second half after a slow first half.
"The only good thing during the first half was that we provoked fouls, and then it was easier for us.
"I just hope that Kosice will win against Gdynia, so we will be third in the group."