They swam stroke for stroke with each other in adjacent lanes, churning the water in unison in the 100-meter freestyle, and even when he had lunged for the wall with his left hand, Alexander Popov of Russia was not sure that he had touched first.
He turned and looked at the scoreboard and thrust his left arm into the air. In the time of 48.74 seconds, the world-record holder had won his first duel with the American Gary Hall Jr. by seven hundredths of a second in defending his Olympic title.
Hall won the silver medal in 48.81 seconds, while Gustavo Borges of Brazil took the bronze in 49.02.
In the 200-meter butterfly, world champion Denis Pankratov claimed Russia's second Olympic swimming gold medal Monday, leading all the way.
Pankratov swept home in 1:56.51, well outside his 1:55.22 world mark.
American Tom Malchow burst through on the final length to snatch the silver in 1:57.44, nipping bronze medalist Scott Goodman of Australia by just four-hundredths of a second.
Frenchman Franck Esposito, bronze medallist at the 1992 Barcelona Olympics and the oldest man in the race at 25, was fourth.
Popov, who is 6 feet 7 inches, got a quicker, smoother start, but Hall, who is 6-6, stuck with him and came off the wall in first place at 50 meters in 23.33 seconds. In the homestretch, they were so close that it was impossible to tell which one was slightly ahead. Like Popov, the rest of the 14,000 spectators at the Georgia Tech Aquatic Center had to wait for the scoreboard as well.
The two will meet again Thursday in the 50-meter freestyle, where experts have given Hall a better chance at victory.
In the morning prelim, Hall and Popov played a little game of one- upsmanship that can be expected from rivals. Hall came out and swam 48.90, the seventh-fastest performance ever. Two heats later, Popov reeled off a 48.74, the fourth-fastest time in history. Then he matched the time in the evening to win the gold medal.
A rivalry has built up between the two, just as it does among track and field sprinters
"He just talks too much," Popov has said.
Hall called Popov "immature" for the mind games he attempts to play with other swimmers, such as staring them down before a race.
The son of Gary Hall Sr., a three-time Olympian, Hall was a reluctant swimmer when he began his career and he has become infamous for a supposedly indifferent attitude toward training. He swam poorly in several pre-Olympic races, but if others were concerned, he was not.
Hall is the grandson of Charles Keating, the 1946 national collegiate champion in the 200-meter butterfly, who is known more infamously as the executive jailed for his role in the Lincoln Savings and Loan scandal in California.