SYDNEY (Reuters) - Usain Bolt's showdown with Justin Gatlin was always going to be the most highly anticipated clash of the world athletics championships in Beijing, but with track and field rocked by recent doping allegations it now looks like being a battle for the very soul of the sport.
The International Association of Athletics Federations (IAAF) hit back robustly at charges it failed to act on hundreds of suspicious tests after data from thousands of blood samples were leaked to media organisations.
Calling the allegations "sensationalist and confusing", the IAAF defended its drugs testing procedures and said it was cooperating with the independent World Anti-Doping Agency (WADA) in an investigation.
What cannot be disputed, however, is that Gatlin is a proven drugs cheat with two positive tests for banned substances that would have resulted in a life ban had he not cooperated with the authorities.
Bolt, on the other hand, is the most bankable track and field athlete of the modern era.
His clean doping record is as much a part of his huge popularity as his undoubted charisma and dominance of men's sprinting for much of the last seven years.
The prospect, therefore, of Gatlin emerging as champion of the blue riband sprint on the evening of Aug. 23 in Beijing could deal another hammer blow to the credibility of the sport.
"You are talking about the most significant, the best loved, best known, most iconic track and field athlete out there, Usain Bolt," Bob Dorfman, a sports marketing expert at Baker Street Advertising in San Francisco, told Reuters.
"So if he got beat by somebody who has had drug issues in the past it wouldn't help the sport."
Unfortunately for the IAAF, that is a scenario which looks to have every chance of panning out.
While world record holder Bolt has struggled to hit his straps this season, the 33-year-old Gatlin is in the form of his life and unbeaten over 100 and 200m since 2013.
"The average person, when they look at his age and see the fact he has been suspended in the past, I think a lot of people are just going to look at it and say, 'well he found a way around the testing,'" said George Belch, a sports marketing professor at San Diego State University.
"Given his age, people are going to have a difficult time accepting the fact that he could be running faster than ever."Even if Gatlin fails to beat Bolt, his compatriot Tyson Gay or Jamaican Asafa Powell might. Both have served doping bans in the last two years.
Bolt has always prided himself on being a "big meeting" runner, however, and could yet rediscover the form that sent him rocketing into the sporting stratosphere on two sultry evenings at the same Bird's Nest stadium in 2008.
Since he won both the 100 and 200m in world record times at the Beijing Olympics, only a false start in the 100 at the 2011 world championships in Daegu prevented Bolt from sweeping the sprint titles at all four major global meetings.
The 28-year-old Jamaican is by far the best-known of the 2,000 athletes expected to compete over the nine days of the championships from Aug. 22-30.
That number is unlikely to drop much despite the IAAF initiating disciplinary action against 28 athletes on Tuesday after re-testing samples from the 2005 and 2007 world championships with new technology.
Most of those responsible for the 32 adverse results have retired or are already serving bans, the IAAF said.
The cloud of doping is sure to hang as heavily as the Beijing smog over the last days of Lamine Diack's 16-year reign as IAAF president, which will come to an end next Wednesday.
Sebastian Coe and Sergey Bubka, two great athletes and Olympians, will contest the election to succeed the Senegalese and take on the task of reviving their sport.
To say that whoever wins will face a challenge tougher than anything they encountered in their much-decorated careers would be something of an understatement.
"Obviously track and field is not a top-of-line sport except during Olympic years," Dorfman added.
"So any sort of scandal is going to hurt the event and is going to hurt it more just because legitimacy is such an issue.
"It's similar to the Tour de France. You talk about cycling and what scandal has done to that sport and how it is just not taken a seriously as it used to be. I would put it in that same category."
Additional reporting by Gene Cherry, editing by Peter Rutherford