At the 1992 Olympic Games in Barcelona, Popov was in only sixth place at the halfway mark of the 100m freestyle, but he came from behind to win. Two days later in the 50m freestyle, Popov led from start to finish earning his second gold medal. He also won two silver medals in relays.
In Atlanta in 1996, Popov defended his 100m title by pulling ahead of Gary Hall, Jr. in the last fifteen metres. He was the first repeat winner of the 100m since Johnny Weissmuller in the 1920s. Three days after that, in the 50m, he powered ahead of Hall again in the final strokes to win his fourth gold medal. And again Popov took home two relay silver medals. One month later, a watermelon vendor stabbed Popov on the streets of Moscow. The knife penetrated 15 centimetres into his stomach and grazed his lung. He recovered sufficiently to win the 100m at the 1998 world championships.
At the 2000 Games in Sydney, Popov earned a silver medal in the 100m freestyle and finished sixth in the 50m freestyle. Popov was elected to the International Olympic Committee and to the IOC's Athletes' Commission in 1999.