In 1957 Erik Petersen joined the KVIK rowing club in København and represented the club for the rest of his life. During his career Petersen competed in the coxless fours, winning multiple Danish championships and gold at the Olympics. He had his best results in 1964, first winning silver at the European Championships in Amsterdam, before going one better at the Tokyo Olympics to win gold with the crew of John Ørsted Hansen, Kurt Helmudt, and Bjørn Borgen Hasløv. In 1970 Petersen, Helmudt, Tom Hindsby, and Poul Nielsen won bronze at the World Rowing Championships in St. Catharines, Ontario.