On July 14, 2014 Yoenis Cespedes successfully defends his title as Home Run Derby champion in the annual event held before the All-Star Game at Target Field in Minneapolis, MN. Cespedes defeats Todd Frazier in the final round, 9 long balls to 1, having hit 28 overall. Ken Griffey Jr. was the only other repeat winner in the event, winning in 1998 and 1999.
Source
Baseball Reference July 14