Paris - Justin Gatlin might have strung together an undefeated run of 25 races since August 2013, but his main rivals in the absence of the injured Usain Bolt believe the American sprinter can be beaten.
Gatlin re-emerged on the track after his second 2006-10 doping ban an athlete possessed, going on to win the 2012 world 60m indoor title, an Olympic 100m bronze at the London Games and world silver in 2013 to add to his 2004 Olympic title and 2005 world sprint double.
At 33, he finds himself in the form of his life and this season is currently the fastest man over both distances having set best times of 9.74 seconds in the Doha 100m in May and 19.57s in the 200m at Eugene in June.
With Bolt struggling with a pelvis problem, there is a glimmer of light for those seeking to overthrow the towering Jamaican who has dominated world sprinting since blasting his way to a golden treble at the 2008 Beijing Olympics.
Fix minor problems
"Is Justin Gatlin unbeatable?" Bolt's Jamaican team-mate Asafa Powell asked ahead of Thursday's Diamond League meet, where he will face both Gatlin and his US team-mate Tyson Gay.
"I don't know who this guy thinks he is, but he is the fifth fastest man so clearly he can be beaten."
The 2007 double world sprint champion Gay, who also served a one-year doping ban reduced for co-operating with the drug authorities, added: "Justin can be beaten anytime but we must admit that he has been running great this season."
Powell himself has also been in sparkling form this season, storming to victory in Paris last weekend.
"I have been running very well this season. I aim to run fast just the same tomorrow (on Thursday). Big races like these are what people pay to see. I am happy to have an early run with the best guys before the big one in Beijing," he said in reference to next month's world championships in the Chinese capital.
"Races like these are important...you get to fix minor problems. Running against the top guys is always good and it helps you to improve."
Back into shape
But Powell added that the head-to-head competition was not something that specifically mattered.
"The idea is to go out there, keep my composure and run my best."
Gay said he was "happy to be racing these two guys, we were supposed to meet a few years ago in Stockholm but it didn't work out. I'm looking forward to the race".
"I'm just gradually getting back into shape. I'm just coming from the US trials and hopefully these guys will push me to a good time tomorrow" (on Thursday).
Like Gatlin, both Gay and Powell are also 33 years old, but neither said that mattered.
"To me age isn't a number or reason why we are doing well. We're just simply running faster than the younger generation and those guys will have to wait until we are done," said Powell, whose aim is to call it a day when he has clocked 130 sub-10sec 100m race -- he's currently the leader on 88.
Gay said he thought the trio's durability was helping them reap dividends.
"I think our age helps us, it gives us experience, we are used to running the rounds and so we get good results at championships," he said.
The American also talked of his pleasure at being taken back into the fold of track and field after serving his ban.
"After the suspension I was welcomed back to the sport with open arms, I'm thankful for that," he said.
"The suspension didn't scar me, I'm just sad I wasn't able to speak out to say it was a mistake and that I did not intentionally take prohibited substances.
"The media needs to help to change the image of the sport," he added. "Everyone makes mistakes, we need to show the kids that you can make a mistake and still bounce back and do well."
Powell, who saw his own doping ban lifted after appealing to the Court of Arbitration for Sport, admitted that "negative headlines" were not good for the sport.
"The 100m is the main event, the attraction at any athletic staging. It's our responsibility as athletes to keep clean and maintain that for a long period that's how we win back the fans: keep clean."