30 Mar 1985
Kim Ji-won beats Ruben Dario Palacio via unanimous decision 15/15
Super Bantamweight (122 lb)
25 May 1990
Luis Mendoza and Ruben Dario Palacio share a draw 12/12
11 Sep 1990
Luis Mendoza beats Ruben Dario Palacio via knockout 3/12
26 Sep 1992
Ruben Dario Palacio beats Colin McMillan via knockout 8/12
Featherweight (126 lb)
Ruben Dario Palacio becomes the WBO Featherweight world champion
1 Jan 1993
Ruben Dario Palacio's WBO Featherweight world title reign ends