Marshall, 29, is the only female boxer to ever beat Shields. Their fight took place in May 2012 during the amateur world championship in China. The British won the battle on points, while for the American it was the first and so far the only defeat in an official bout. Until the end of her Olympic career and in the professional ring, the boxer from the United States has not yet suffered a single defeat.
Marshall currently owns the WBO middleweight championship belt. Shields combined all of the major light middleweight titles in her last performance.