Biba turned on the style in the first half when she poured in 16 of her team-high 18 points to help UMMC take command at 42-25.
She has been on fire from long range, making 52.4% (11 of 21) on the season.
Latvia international Zane Tamane and Amber Holt helped Sopron stay within striking distance by scoring nine and seven points, respectively.
They trailed by 12 at the break.
Tamane would end up leading Sopron with 18 points and 13 rebounds.
There was no way to counter the depth and talent of UMMC, however.
Sopron trailed by as many as 19 points in the third quarter and 22 in the fourth.
When it was over, UMMC had five players in double figures in points.
Crystal Langhorne finished with 17, Sandrine Gruda and Maria Stepanova 16 and Cappie Pondexter 11. Gruda also had a team-high 11 rebounds.
In addition to Tamane, Sopron got 14 points and 12 boards from Angel McCoughtry.
The USA international struggled shooting the ball, though, making five of her 17 shots from the floor and missing both three-pointers.
The UMMC defense shut down Sopron, limiting them to 19 of 56 (33.9%) shooting from the field. They were one of 10 from long range in losing for the second week in a row - albeit to tough opposition.
Fener beat them last week in Istanbul, 89-72.