by Rob Woollard
ATHENS, Aug 22 (AFP) - A new drug scandal exploded at the Olympic Games here Sunday, overshadowing the battle on the athletics track for the coveted accolade of being the world's fastest man.
An International Olympic Committee (IOC) medical source said Russian women's shot put gold medallist Irina Korzhanenko had tested positive for a banned substance.
It is the first time since the Ben Johnson scandal at the 1988 Seoul Games that a gold medallist in the Olympics' showpiece track and field competition has failed a drugs test.
Ironically, Korzhanenko was reported to have tested positive for the banned steroid stanozolol -- the same substance that fuelled Johnson on his infamous dash to gold in the men's 100m final 16 years ago.
Korzhanenko's case makes her the 14th athlete to be caught since an Olympics anti-drugs sweep began on July 30.
The new doping controversy diverted attention away from the athletics arena Sunday as day nine got underway with one of the most open 100m finals in years due to take place at 11:10 pm (2010 GMT).
The race will see Maurice Greene of the United States attempt to become only the second man in history to successfully defend his Olympic crown provided he comes through the semi-final rounds safely.
Only one other runner -- Carl Lewis in 1984 and 1988 -- has won back-to-back 100m golds and Greene will face a stiff challenge to hang on to his title.
American team-mate Shawn Crawford set the early pace in heats on Saturday but a clutch of Caribbean sprinters led by Jamaican Asafa Powell and world champion Kim Collins looked in superb form.
A total of 28 gold medals were to be decided Sunday, with the United States and China jostling for position at the top of the standings.
Sunday's competition saw China win its 100th gold medal since joining the Olympics in Los Angeles 20 years ago, adding two more to its overnight tally of 18 golds.
World number one Zhang Yining brought the century up with victory in the final of the women's singles table tennis tournament but greeted the milestone with a hint of indifference.
"I think this makes my gold medal more interesting but to me, whether it is the 100th or the first, a gold medal is a gold medal so they all have the same significance," she said.
Britain will meanwhile be banking on long distance queen Paula Radcliffe to bring home the team's sixth gold medal of the games when the women's marathon takes place.
The United States was level with China on 20 gold medals after their men's eight rowing team won the event for the first time since 1964.
The American team included Jason Read, a New Jersey fire chief who toiled in the wreckage and the carnage of the ruins of the World Trade Centre.
"It's the first gold medal for the United States for 40 years in this event and we are very excited. It's amazing," said Read. "It was a very difficult race with very good opponents. We went for it and we did it."
Chile meanwhile was celebrating its first ever Olympic gold medal Sunday after the late-night men's doubles tennis final won by Nicolas Massu and Fernando Gonzalez.
The South Americans defeated Germany's Nicolas Kiefer and Rainer Schuettler 6-2, 4-6, 3-6, 7-6 (9/7) 6-4 in an epic final that saw them save four match points in the tie-break.
The match started at 11:00 pm and finished at around 2:40 am with Massu aand Gonzalez throwing themselves into each other's arms and rolling on the court.
Massu has to gird himself for a chance at another gold medal when he plays Mardy Fish of the United States in Sunday's men's singles final.