UNICS Kazan overcame an early deficit to down Arsenal 96-93 and claim a 2-0 lead in their best-of-five Superleague quarter-final play-off series.
The hosts, who are among the four sides still in contention for the FIBA Europe League title, dominated the second quarter and led 48-41 lead at half-time before running away with the match in the final period.
Samoilenko led the way with 19 points, 10 rebounds and three assists while Lithuanian international Saulius Stombergas and Kristofer Ensti provided good support.
Stombergas led all scorers with 20 points and Ensti contributed 17.
For Arsenal, Roy Hairstone top-scored with 17 points.