The game on 14 September was marred by violence and saw two players sent off. Brive, who won 32-31, also claimed that three of their players were injured in a bar fight after the match. Three Welsh players were charged with assault.
The clubs were each fined pounds 30,000 for the trouble during the match and warned about their future conduct.
Brive initially said they would not travel to Wales for the return match but did so and drew 29-29 in a trouble-free encounter.
In the other play-offs, Leicester host Glasgow while Cardiff make the short trip to Llanelli.
Wasps, Bath, Harlequins, Toulouse and Pau won their qualifying groups to go straight into the last eight.Reuse content