Watch the American team of Shamier Little, Olivia Baker, Shakima Wimbley, and Kendall Baisden take on the World's best and come through as the champions at meet end in the 4x400 meter relay finals with a World Junior leading time of 3:30.42. Race video above and post-race video interview below with the U.S. quartet after their victory at the 2014 IAAF World Junior Championships.