[Story by Julie Goldsticker/USA Boxing] (COLORADO SPRINGS, COLO.) – Team USA enjoyed an undefeated day at the 2014 Youth World Championships in Sofia, Bulgaria on Thursday with two American athletes recording opening round wins. 2013 Junior World Champion Shakur Stevenson (Newark, N.J.) and 2014 Youth Continental titlist Martha Fabela (Oakland, Calif.) each defeated their preliminary