Monte Carlo - Justin Gatlin fired out a warning to Usain Bolt in the troubled world of track and field with an impressive victory in the 100m in 9.94 sec at the Monaco Diamond League meet on Friday.
The field for the men's blue riband event has been stripped of three of its finest proponents in the last week.
American Tyson Gay, the second fastest sprinter ever, and Jamaican ex-world record holder Asafa Powell, the fourth fastest, were revealed as having failed doping tests last week.
And then defending world 100m champion Yohan Blake pulled out injured, leaving Gatlin in prime position to push six-time Olympic and five-time world gold medallist Bolt all the way at next month's world championships in Moscow.
Track and field officials will doubtless be wishing more for a Bolt victory than one by Gatlin, the 2004 Olympic champion who served a four-year ban for doping before claiming bronze at the London Olympics.
But having already nipped Bolt in the Rome Diamond League, Gatlin again showcased his slim-lined approach, away cleanly from the start in balmy conditions, head down for the 30 metres before slowly coming up as he powered into his drive phase.
"I felt really good out there," said the 31-year-old Gatlin, who has also won the world 60m indoor title twice, in 2003 and 2012.
"I think I can still improve on my technique but I'm just coming back from a hamstring injury."
Gatlin was pushed all the way, however, no doubt affected by having run the anchor leg for a US 4x100m relay team earlier in the evening.
"To run the relay and the 100m the way I did, well I think it proves I'm ready for the world championships," he added.
Teammate Dentarius Locke came in second at just 0.02sec, with Frenchman Jimmy Vicaut again dipping under the 10sec-mark, this time by one-hundredth.
Another American Mike Rodgers, who also picked up a nine-month ban for testing positive for a banned stimulant, was fourth ahead of St Kitts and Nevis veteran Kim Collins and Jamaicans Nickel Ashmeade and Kemar Bailey-Cole.
Gatlin, who on Thursday wished Gay and Powell "all the best in stressful times" in the wake of their failed drugs tests, had opened his night by leading home the US 4x100m relay team in a world leading time of 37.58sec.
"I think with a team like this we can do some real damage in Moscow," he said of his outing.