Ivanov started as a boxer, in 1950. Starting from 1952 he combined boxing with rowing, eventually chose the latter sport. By 1955, at the age of 17, he won the USSR junior championships and finished third in the senior championships, beating the Olympic single scull champion Yuriy Tyukalov in the process. In 1956, he won his first Soviet and European titles and an Olympic gold medal. At the Olympics he was in fourth place at the 1500 meter mark. With only 500 meters left, he began a devastating sprint, catching Teodor Kocerka, John B. Kelly Jr., and then Stuart MacKenzie who had led the entire race. At the award ceremony, excited, Ivanov dropped his gold medal into Lake Wendouree, where the race took place. His diving attempts to rescue the medal failed, and the IOC later provided him with a replacement. After the Olympics Mackenzie consistently defeated Ivanov at the Henley Royal Regatta and at the European Rowing Championships in 1957 and 1958. Disappointed by his losses, Ivanov was considering to retire, but was brought back to shape by his coach Arkady Nikolayev. In 1959 Ivanov regained the European title. He also set a world best time of 6:58.8 for a 2000 m single scull race, becoming the first person to break the seven-minute barrier. At the 1960 Olympics, Ivanov won again with a blistering sprint, defeating Achim Hill by more than 6 seconds. Mackenzie withdrew because of illness. In 1962, Ivanov won the first ever World Rowing Championship, defeating Mackenzie and Seymour Cromwell. At the 1963 European Rowing Championships, he came fourth. Ivanov faced Hill again at the 1964 Olympics. This time he trailed Hill by 7 seconds with 500 mto go, but finished 3.73 seconds ahead owing to his trademark sprint. Ivanov missed the 1965 European Rowing Championships due to illness. Ivanov was hoping to compete at the 1968 Olympics, but was left out of the Soviet team in favor of a younger rower. Melnikov failed to reach the Olympic final, while Ivanov retired next year. In addition to the Olympics, Ivanov won 11 Soviet single scull titles and 4 European titles. He was awarded the Order of the Red Banner of Labour and two Orders of the Badge of Honor.
Life after retirement
In 1960, at the peak of his rowing career, Ivanov graduated from a military school, and in 1969 received his master's degree from the Volgograd Institute of Physical Education. After retiring from competitions he served as a navy officer and retired in the rank of captain. He then resumed competing in rowing in the masters category.