The Russian is only the third man in Olympic history to win the blue riband at successive Games, the most famous of his predecessors being Johnny Weissmuller, who went on to further fame playing the film role of Tarzan.
Hall, who is known as a one-length sprinter, led to the turn but was overhauled by Popov in the final 20 metres.
There was more disappointment for Britain's women, when Sarah Hardcastle, swimming in the same heat as Janet Evans and Michelle Smith, missed out on a place in the 400m final, but her 4:14.50 is her fastest over the distance in a morning and she had the consolation of winning the B final. That, at least, was encouagement for her best event, the 800m tomorrow.
"It was a good time for me and Hayley Lewis, who is one of the big threats in the 800, didn't perform that well," she said. "If I can step up the endurance work over the next few days I'll be fine."
Asked about the mood in the British camp after a less than scintillating start to the Games, she said. "Generally it's really good. OK, we haven't won any medals but there have been a few personal bests and you can't really ask any more from people."
James Hickman reached the final of the 200m butterfly, beating the world record holder, Russia's Denis Pankratov, while setting a British record of 1min 58.16.
The swimmer Dawn Fraser, Australia's most successful Olympian, was admitted to an Atlanta hospital yesterday apparently with chest pains. Team officials said Fraser, 58, had asked for a check-up and there was "no cause for alarm".
"The hospital says she's quite OK, she's being monitored," one team official said. Fraser was among 10 Olympians honoured at Friday's opening ceremony in Atlanta and is working as an athletes' liaison officer during the Games.Reuse content