Track is back and it's shaping up for a sizzling summer. World Cup years, wedged right in between Olympics, are generally periods when the sport takes a back seat. And with the pervading whiff of doping scandals and the sport's struggle to replace megastars such as Carl Lewis and Michael Johnson, athletics has lost its lustre. But finally two men are offering up a fascinating rivalry that has the potential to provide the unchallenged highlight in Beijing. So who is the world's fastest human? Is it American Justin Gatlin or Jamaica's Asafa Powell? For the moment at least it belongs to them both - a prize split right down the middle, leaving intense rivals locked in an uneasy partnership. Gatlin won the Athens Olympics title, with Powell trailing in fifth place, and then took a world championship gold medal home from Helsinki last year. Powell, plagued by recurring injuries, came back with a bang last June when he ran 9.77 seconds in Athens to claim the 100 metres world record. Gatlin, the pundits opined, couldn't run record-breaking times but had the ability to come through in big races. As for Powell, he was the world's fastest man on a good day, but he lacked courage and choked on the big stage. Both men vehemently disagree with those assessments and, like heavyweights before a bout, have filled the air with rants and braggadocio. Then a couple of weeks ago Gatlin went to Doha and seemed to pip Powell's record by a whisker. Not so fast, officials said - five days after he was crowned the world record holder and images of Gatlin standing beside a Tissot clock showing 9.76 seconds were beamed around the world, they admitted they had messed up. Gatlin clocked 9.766 seconds but the IAAF does not register times to the thousandth of a second, so they are rounded up to the nearest hundred. So his official time was 9.77, precisely the same as Powell's. Why it took them so long to work out that a bungling timing official had rounded down instead of up is a mystery, and it's also surprising that in this day and age adequately sophisticated machinery cannot be found to measure an event of this significance to the thousandth of the second. Adding to the farcical nature of events, Gatlin's manager has demanded an enquiry into Powell's record, insisting his time was also rounded down instead of up. It's all a bit of a mess, but the good news for the sport is the whole affair has added some spice and drama to their rivalry. Gatlin is only 24 and Powell is a year younger, so they have plenty of time to shave milliseconds off their personal bests. Both men say they have a lot more in the tank and are talking about hitting times in the region of 9.70 within a few months. The way they're shaping up you'd be inclined to believe they can do it. The battle, in a somewhat bizarre form, starts today in Oregon. They will race on the same track, but not in the same race, because they are contracted to go head-to-head in Gateshead, England, next month and the terms of the deal forbid them from clashing before then. This offers the intriguing possibility of Gatlin breaking the world record today watched by Powell, who then dons his spikes and goes one better. Fascinating stuff, indeed. But clearly not as mouth-watering a prospect as seeing the two sprinters going shoulder to shoulder down the straight. For that we'll likely have to wait until Gateshead, where they have been induced by appearance fees of more than #100,000 ($1.44 million) to meet. With conditions in the north of England often blustery and cool, the track is not one where records tend to fall. For that we might have to wait for July when the pair are once again lined up in the blisteringly fast track in Athens, with the athletes helped along by a warm climate and often decent tailwinds. The men are hot commodities and over the past couple of weeks promoters have invited them to more than 400 events around the globe, dangling huge financial incentives. To ramp up the drama, their managers have agreed to only letting them meet two or three times a season, which will mean they will probably have had just a handful of encounters before they fight for the ultimate prize on the Beijing stage in two year's time - and a ticket into the Bird's Nest for that occasion would certainly be something to savour. Unfortunately, it is virtually impossible these days to mention athletes without building in a caveat on doping. We hope and want to believe these two men have fought their way to the top by fair means. Suspicions abound, nonetheless. Gatlin, for instance, is coached by Trevor Graham, who in 2003 sent a syringe containing the designer steroid THG to the US Anti-Doping Agency, triggering the Balco investigation. Was Graham motivated by the desire to clean up the sport or was he seeking revenge after he had fallen out with his star athlete and world-record holder at the time, Tim Montgomery? The jury is still out on that one, and we'll probably never know, but we do know that at least eight athletes coached by Graham have since tested positive for banned substances. Graham also used to train Marion Jones, against whom there is a mountain of circumstantial evidence to suggest that steroids helped her win five Olympic medals. Gatlin has never tested positive for steroids, but five years ago he did test positive for an amphetamine contained in medicine he had been taking since he was a child for attention deficit disorder. He was suspended for two years but he appealed and it was lifted after 12 months. He swears blind he is clean and speaks at length about how important it is for the credibility of athletics that he and others at the top level keep producing negative results at doping tests. 'If I ever tested positive I understand it would be one of the hardest hits our sport could take,' he said recently. 'It could be the killer blow.' He's right. The fans crave heroes like him and Powell. Like jilted lovers they've been hurt before and don't know if they're ready to risk going through it again. They need them to be clean. Oh, and while we're at it, time-keepers who know the rules would be nice, too.