Wednesday, she won the gold medal in the women's shot put competition; Monday, she lost it, as officials stripped her of the honor after two different samples showed she tested positive for use of the steroid stanozolol.
Korzhanenko, who served a previous two-year drug suspension, faces a lifetime ban from the sport. In 1999, she was stripped of the silver medal at the world indoor championships for a doping violation and was given a two-year suspension that kept her out of the 2000 Sydney Olympics.
Under international rules, two steroid violations warrants a lifetime ban.
Another female shot putter, Uzbekistan's Olga Shchukina, tested positive in a pre-event screening for the steroid clenbuterol. She finished 19th and last in her qualifying group and was expelled from the games Friday.
The gold medal now goes to Cuba's Yumileidi Cumba Jay. Germany's Nadine Kleinert would move up to silver, and Russia's Svetlana Krivelyova to bronze.
The IOC decision came a day after Greek weightlifter Leonidas Sampanis became the first athlete of the Athens Games to be stripped of a medal for a doping offense. Sampanis lost his bronze medal in the 137-pound (62kg) category.
So far, nine weightlifters have failed drug tests, including another Russian, Albina Khomich. A Kenyan boxer was also sent home for using drugs. With six days left in the games, including track and field events, more positives are likely.
"The testing is more extensive and more comprehensive, so you'd expect we would catch more athletes that are cheating," says Dick Pound, chief of the World Anti-Doping Agency. "It increases the confidence in the authenticity of the competition if we are taking people out who cheated."
In other results from the Games:
Men's 100-Meter Run
Justin Gatlin shoveled the snow off his track in North Carolina, braving the cold to keep practicing, keep working, keep chasing Olympic gold.
He finally caught it Sunday night, outrunning the fastest field in Olympic history to become the youngest 100-meter champion in 36 years.
Gatlin ran a personal best 9.85 seconds, barely holding off Portugal's Francis Obikwelu, defending gold medalist Maurice Greene, outspoken teammate Shawn Crawford and Jamaica's Asafa Powell.
It was the first time in Olympic history that five men broke 10 seconds in a race. Four did it at the 1996 Atlanta Games.
Obikwelu finished in 9.86 for silver. Greene took bronze in 9.87 and Crawford was fourth in 9.89.
"I said it was going to be the most exciting race in the world, and it was," said Gatlin, a 22-year-old Brooklyn, N.Y. native who now lives in Raleigh, N.C. "This is what I train for, that's why I shoveled the snow off North Carolina tracks. That's why I'm here. I'm here to win the gold medal."
Women's 20-Kilometer Walk
Athanasia Tsoumeleka of Greece got the crowd going early Monday, winning the 20-kilometer walk in 1 hour, 29.12 seconds, then parading around the stadium with a Greek flag. Olimpiada Ivanova of Russia won the silver in a time of 1:29.16, while Australia's Jane Saville took bronze with 1:29.25.
Training with her dog high in the Sierras, then dodging herds of sheep on runs through the hills of Crete in the days before the Olympics, Deena Kastor kept believing she could earn a medal in the marathon.
"I couldn't have prepared myself any better," the former Arkansas Lady Razorback said during a break in her Crete training.
Two weeks later, Kastor conquered the rugged hills of the ancient course that gave the marathon its name, somehow marshaling the energy to pull from eighth to third in the final few miles and earn the bronze - the first U.S. marathon medal in 20 years.
Mizuki Noguchi of Japan held off Kenya's Catherine Ndereba to win the gold, but Kastor was gaining on them at the end. Ndereba took the silver, reversing the order of last year's world championships, where the Kenyan won and Noguchi was second.
Noguchi, who ran the course as a warmup in June, won in 2 hours, 26 minutes, 20 seconds. She was 49 seconds ahead of Ndereba, who narrowed the lead to 14 seconds late in the race but could get no closer.
Kastor, who overtook Ethiopian Elfenish Alemu with less than a mile remaining in the 26.2-mile race, finished in 2:27.19. Her bronze was the first marathon medal for an American since Joan Benoit's gold in 1984.
"It's incredible," said Kastor, an ultra-thin, exceedingly gracious 31-year-old. "I was in tears the whole last lap."
The favorite, British world record holder Paula Radcliffe, faded to fourth place and then quit about 3½ miles (six kilometers) from the finish, bursting into tears, then sitting on a curb and sobbing.
The race begua in the heat of early evening in the town of Marathon.
This was the first time women have raced the ancient course over which, it is said, Pheidippides carried the news in 490 B.C. that the Greeks had defeated the Persians in the Battle of Marathon.
"Be joyful. We win!" Pheidippides shouted.
Then he dropped dead.
Canada is guaranteed at least a silver medal in women's wrestling after Tonya Verbeek advanced to the final in the 55-kilogram division at the Summer Olympics on Monday.
Verbeek, of Beamsville, Ontario, defeated Ida-Theeres Karlsson of Sweden 3-1 in the semifinals and will face Saori Yoshida of Japan, one of the best female wrestlers in the world, in the final later Monday.
In the other semifinal, Yoshida defeated Anna Gomis of France 7-6 in a tight bout.
Yoshida is a two-time world champion, defeating American Tina George in the finals at both the 2002 and 2003 worlds. Yoshida has never lost to a wrestler from outside Japan, winning all 15 of the international competitions she has entered.
Overall Medal Count
Halfway through the games, the race is shaping up - as expected - between the United States, China and Russia.
As competition resumed on Monday morning, the United States led with 58 medals - 21 gold, 22 silver, 15 bronze. China had 46 overall - 22 gold, 14 silver, 10 bronze. Russia dropped back to 36 medals overall - six gold, 13 silver, 17 bronze.
Although Russia is behind, some of its best disciplines are still coming up, so there are plenty of chances to close the gap.
"I think it's going to be a three-horse race," said Steve Roush, managing director of sport performance for the U.S. Olympic Committee. "It's a matter of a few medals that will separate first, second and third."
In Sydney, the United States wound up with 97 medals, including 39 golds. This time, the Americans are trying to beat that, setting a lofty goal of 100 medals. Roush said disappointing performances at the track Saturday didn't change that.
"It's still obtainable," he said.