Beijing - US sprinter Justin Gatlin clinched first place in the men's 100 metre sprint Wednesday at the 2016 IAAF World Challenge in Beijing, as he accelerates to an Olympic showdown with arch rival Usain Bolt.
Days after cruising to victory at the Diamond League event in Shanghai, the 34-year-old veteran ran 9.94sec, but fell short of beating the year's fastest time of 9.91sec set by Femi Ogunode of Qatar.
Gatlin has struggled to shake off controversy for previously failing two dope tests, but when asked Wednesday about news that 31 athletes in six sports could face Olympic bans for doping, he said: "I've just been focused on the season thus far."
He added "I think that the IAAF and the IOC are doing their job" to ensure that in Rio "all the athletes will be comfortable when it comes to competing against each other".
Asked how he maintained his fitness in his 30s, he said: "Simple. I like to win. I like winning. I like the feel of it."
Delayed by two false starts in the 100m that saw American Deondre Batson disqualified, Gatlin ran compatriot Mike Rodgers into a close second, followed in third by Chinese sprinter Xie Zhenye who set a personal best.
Gatlin is seeking to dust himself off after double disappointment at the world championships last year, where he lost both the 100m and 200m to Jamaica's Bolt, adding extra spice to their expected meeting in Rio.
Gatlin has failed two dope tests during his career but has returned to competition and represented the United States at the 2012 Olympics.
Meanwhile world record holder and Olympic champion Aries Merritt recovered from a disqualification days earlier in Shanghai to triumph in the men's 110m hurdles with a time of 13.24sec, ahead of Xie Wenjun of China.
The result was a positive sign for the Olympic aims of the 30-year-old American, who recovered from a kidney transplant last September and is seeking a return to glory.
"I'm now recovering well," he said in Beijing before the race. "My goal for Rio is obviously to make the US team win again."
Previously in Shanghai he had said the long recovery process put him "months behind my competitors".
In the women's 200m sprint, Veronica Campbell-Brown of Jamaica bounced back from her defeat in Shanghai to win easily, breezing to first in 22.29sec.
The men's pole vault saw 23-year-old Sam Kendricks of the US score another triumph after his surprise win in Shanghai, breaking his days-old personal best with a vault of 5.92m.
Last year's world championship winner Shawn Barber of Canada again disappointed after a third-place finish in Shanghai, vaulting 5.60m for sixth place.
Chinese athletes put in a solid pre-Olympic performances. In the triple jump Dong Bin came first with a jump of 17.24m, while 2008 Olympic bronze medallist Zhang Wenxiu won the women's hammer throw with a 75.58m toss.
Majd Eddin Ghazal of Syria, the country's flag-bearer at the London 2012 Games, soared above the rest of the field in the men's high jump, leaping a personal best 2.36m in front of a cheering crowd.