What boxer defeated Gilbert Choombe in the 2012 Olympics along with Manny Pacquiao in a unanimous decision?
Gilbert Choombe:  He competed in the Men's light welterweight event at the 2012 Summer Olympics but lost to Jeff Horn in the first round. Jeff Horn:  He has held the WBO welterweight title since July 2017, after defeating Manny Pacquiao in a unanimous decision.
Jeff Horn