In 2013, Dershwitz fenced in men's sabre at the 2013 World Fencing Championships, where he finished 36th after a 15-12 loss to Matyas Szabo (Germany). He was also the youngest member of the US national team in 2013, at 17 years of age. Dershwitz also competed in men's sabre at the 2014 World Fencing Championships in Kazan, Russia, in men's sabre at the 2015 World Fencing Championships in Moscow, Russia, and in the 2016 Senior Team World Championships in Rio de Janeiro. He won a silver medal in saber at the 2018 World Fencing Championships in China.