Light heavyweight champion Oleksandr Gvozdyk (16-0, 13 KOs), 31, of Ukraine, due to make his first defense March 30 in the main event of a Top Rank Boxing on ESPN card at Philadelphia's 2300 Arena, will face Doudou Ngumbu (38-8, 14 KOs), multiple sources with knowledge of the bout, which has been agreed to but not signed, told ESPN. Ngumbu, 37, a Congo native based in France, is coming off a decision win over then-unbeaten Yoann Kongolo in May to rebound from a decision loss to former title challenger Igor Mikhalkin, who has defeated him twice. Ngumbu has also lost to former title challengers Isaac Chilemba, Andrzej Fonfara and Nadjib Mohammedi.