BRUSSELS - American sprinter Justin Gatlin admitted that his failure at the World Championships was "a hard lesson", adding that he had learned and moved on.

Usain Bolt of Jamaica (R), gold medal, reacts as he poses on the podium next to Justin Gatlin of the US, silver medal, after the men's 200 metres event during the 15th IAAF World Championships at the National Stadium in Beijing, China, August 28, 2015.??[Photo/Agencies]

Gatlin, the double reigning champion here in Brussels told a pre-event press conference on Thursday that he had been focusing on preparing for the races at the season finale of the IAAF Diamond League.

"After Beijing I felt fatigue, not emotionally but physically," said the double runners-up at the Beijing worlds. "I can't dwell on my past performances and I try to look at the next race. I was happy with my level of performance and that I came away without injuries."

The former world and Olympic champion lost his first race since the 2013 world championships when he stumbled on the last five meters at the 100m final on August 23 before he was beaten again by Usian Bolt in the 200m race.

"Of course I did not race in Beijing the way that I used to. In the closing stages of my race I was leaning forward too much," said Gatlin. "I have to think more about executing my own race instead of competing against other athletes. It was a hard lesson, but I have learned."

The 33-year old spent 11 days at home resting and said he was ready for the challenge to defend both titles on Friday's Diamond League meeting.

"It will be a big challenge after coming off a double at the world championships and running so much more this year than last year, but I am here and ready to run. I hope the body hold up."

Comparing to the event titles, Gatlin was even closer to the Diamond trophy as he was holding a comfortable lead of six points in the 100m standings, which means a third place in the Belgian capital would be enough to claim the Diamond title.