In Cartagena at the 2006 Caribbean Games, the 212 lbs Rivas lost in the first round to Cuban Olympic Bronze medalist Michel López Núñez 4:6.

[2] On 4 February 2007 at a PanAm qualifier Rivas scored his first big win by beating two-time American champ Mike Wilson 24:19 but lost to Cuban Robert Alfonso 12:21.

[3] In the Pan-American main event in Rio he beat Gerardo Bisbal 22:8, Didier Bence by walkover (injured) and reached the final but lost to Alfonso once again, this time 4:8.

[4] In Chicago, at the 2007 AIBA World Boxing Championships he stopped Dominican Lequan Carlisle but lost to eventual silver medalist Vyacheslav Glazkov 7:23.

[16] On 22 October 2021, Rivas outpointed undefeated Ryan Rozicki to a unanimous decision with scores of 116–111 and 115–112 twice to become the inaugural WBC bridgerweight champion.