In what may be a first, Duiven Sr. himself had opened the show two hours before in a fight against his own son, 19-year-old prospect Harry Duiven Jr. (6-1, 4 KOs). The unusual matchup came about after the pull-out of Duiven Jr.'s original opponent Rocky Ven (39). Astonishingly the Duivens went at it on full throttle and Junior scored a TKO in round two.
Souce: www.fightnews.com