The 28 year old Lopez, a hard-hitting southpaw lost his title in a stunning upset to Orlando Salido of Mexico last April 16 when the bout was stopped by referee Roberto Ramirez Jr at 1:30 of the eighth round with Juanma standing but taking a beating from Salido.
At the time of the stoppage all three judges had the fight dead even at 66-66.
Lopez who is ranked No. 4 by the WBO made no mistake against the No. 13 ranked Oliver in what looked like a mismatch.
Juanma dropped Oliver twice in the opening round and the fight was stopped after Lopez dropped the American one more time at 2:32 of round two. The referee was once again Roberto Ramirez Jr.
The win improved Lopez’ record to 31-1 with 28 knockouts while the 31 year old Oliver, also a southpaw, dropped to 25-3 with 8 knockouts.