An undergarment is provided having a support system configured to comfortably support a male wearer's genitalia throughout aggressive athletic movements. Inside of the undergarment, an internal pocket is formed by a generally H-shaped insert that holds the male wearer's genitalia in a forward position and keeps the wearer's genitalia aligned with the internal portion of the athletic cup positioned at the front of the undergarment. Additionally, the H-shaped insert positions the male wearer's genitalia away from their legs, providing increased support and comfort for the wearer. A cross-wall defining the back of the internal pocket holds the wearer's genitalia to prevent it from dropping backward or downward, and presses against the wearer's perineum at its top edge to further aid in creation of a barrier that even further reduces the risk of chaffing. The side panels of the H-shaped insert are so positioned with respect to the wearer's anatomy so as to pull the back portion of the undergarment forward against the wearer's buttocks, and the bottom portion of the undergarment upward against the bottom of the wearer's torso (and particularly against the wearer's perineum), when worn.