The win allowed Ekaterinburg to clinch first place in Group C with a 9-1 record while Union Hainaut, already eliminated from contention for a place in the Eighth-Finals, slumped to 3-7.
Laurent Buffard's Ekaterinburg trailed 2-1 but then scored 17 straight points - five by Asjha Jones - to take command.
After Sabrina Reghaissia stopped the rot with a basket for Union Hainaut, Ekaterinburg finished the quarter by scoring eight more points for a 26-4 stranglehold on the game.
The advantage ballooned to 30-4 early in the second quarter before Vedrana Grgin Fonseca hit a three-pointer for Union Hainaut.
When Ekaterinburg's Agnieszka Bibrzycka caught a pass from Cappie Pondexter and hit a three-pointer with four seconds to play in the first half, the Russians had a 55-12 lead.
The rest of the game was an exercise in damage limitation for Union Hainaut, who hail from the proud basketball city of Valenciennes.
Buffard coached US Valenciennes before taking the helm of Ekaterinburg ahead of the 2007-08 campaign.
Sandrine Gruda, a former USVO player, ended up leading Ekaterinburg with 15 points - 13 of which were scored when the hosts already had opened up an advantage of 36.
The scoring attack was balanced, with Russia internationals Maria Stepanova and Svetlana Abrosimova each pouring in 11 points.
Bibrzycka, who played just over 12 minutes, had all 10 of her points in the first half.
Ekaterinburg were 23 of 39 (58.9%) inside the arc, seven of 15 (46.6%) beyond it and 18 of 23 (78.2%) at the free throw line.
Union Hainaut were 10 of 38 (26.3%) from two-point range and 10 of 18 (55.5%) from three-point land.
They took far less trips to the charity stripe and ended up six of 11 (54.5%).
Ekaterinburg out-rebounded Union Hainaut 40-24, with Stepanova pulling down seven and Jones six. Pondexter, Gruda and Yelena Leuchanka each had five rebounds.
UMMC Ekaterinburg coach, Laurent Buffard:
"We played well in the first half. We had hoped to have a greater advantage, but in the second half we allowed the oponents to make 10 three-pointers."
Union Hainaut Basket coach, Fabrice Courcier:
"We knew the match would be difficult. UMMC is a very serious team, and we have problems both in defense and offense. We started slowly, but began to play more aggressively after the break."