BEIJING (AFP) - Usain Bolt comes to the world championships in Beijing caught in the crosshairs of controversial rival Justin Gatlin in what promises to be one of the closest fought sprint rivalries seen in a long time.
Bolt has dominated sprinting over the past seven years since he claimed a golden treble at the 2008 Olympics held at the same Bird's Nest stadium that will stage the worlds between August 22-30.
The towering Jamaican went on to claim an unprecedented second treble at the London Games in 2012 and has won every world sprint and relay title on offer, bar a hiccup in the 100m in the 2011 Daegu worlds when he was disqualified after a false start.
Bolt, who has held the 100m and 200m world records since 2009, last month roared back from an early season pelvic injury that saw him miss six weeks of competitive action with back-to-back 100m times of 9.87sec at the London Diamond League meeting.
"I am still number one," insisted the 28-year-old. "I will continue being number one. Until I retire, that's the plan.
"It does help the confidence," he said of his successful return to the track in London ahead of Beijing. "I have been putting in the work and I can see it is coming out on the track. It definitely looks good."
On 100m times recorded in 2015, Bolt is now ranked number six, Gatlin topping the list with a personal best of 9.74sec set in Doha in May, having also clocked 9.75 twice and 9.78.
Gatlin cuts a controversial figure on the track scene, readily admitting that a four-year doping ban served between 2006-10 after a positive test for testosterone had been both "a gift and a curse".
The Florida-based sprinter has since hit the peak of his form at the age of 33 and has established himself as firm favourite in both the 100 and 200m on the back of an unbeaten streak of 27 races dating back to August 2013.
With Bolt's early-season injury concerns and the loaded schedule of races to be run in the Chinese capital, the American is confident of adding to a medal haul that includes 2004 Olympic 100m gold, 2005 world sprint double golds, 2012 world 60m indoor gold, London Olympic 100m bronze and Moscow world silver.
"My body feels it's like a 27-year-old instead of a 33-year-old who's run those four years and feels tired," Gatlin told AFP in an interview last month of his longevity and current prowess.
"My being away from the sport has been a gift and a curse in a way. For me it's saddening I had to be away, but I'm able to have had adequate rest and sit back and see my opponents and their growth and use that to my advantage."
There is never a shortage of people willing to shoot Gatlin down. He was shunned by organisers of this month's London Anniversary Games, when Bolt made his comeback.
And track and field's governing body, the IAAF, recently changed their rules for their prestigious Athlete of the Year awards, insisting that a convicted doping cheat was not eligible.
Gatlin is quick to deflect talk of that issue to his rival Bolt.
"One thing I can say about Usain is that he is a gamer, he's a showman, he'll rise to the occasion when it's time to do so. All that other stuff is not pressure for him," he told AFP.
"Usain woke up in the semi-finals in London in 2012 and went out there and did what he had to do and I predict (he'll be planning to do) the same thing for Beijing."
Bolt is in no doubt what he has in mind, with reports he has been stopping the clock at 9.7sec on the training track, an assertion he declined to dismiss.
"I have been running fast," he said. "I can't say I haven't been running fast in training.
"I'm ready to go (to Beijing) and I'm ready to win."
