The meeting, which took place in Kazan, the outcome of which was decided in overtime, ended with a score of 76:73 in favor of the guests.
As part of UNICS, John Brown and Jordan Morgan scored 17 points.
Nate Walters brought 15 more points to the team.
Xabi Lopez-Arostegui scored 16 points for Hoventud.
Another 15 points were brought to the team by Vladimir Brodzianski.
Nenad Dimitrievich has 14 points.
This is the second defeat for the Kazan team this season with two victories.
Another game has been postponed due to the coronavirus.
The next contender for UNICS will be the Italian Reyer.
Earlier it was reported that Khimki suffered their fifth defeat in the Euroleague, losing to Maccabi.