World 100m champion Usain Bolt has admitted that his triumph over Justin Gatlin in Beijing is "a big deal".

The Jamaican had looked off form in the early rounds at the World Athletics Championships, but was able to beat the controversial American, who has served two drugs bans, by 0.01s in Sunday's final at the Olympic Stadium.

Speaking afterwards, Bolt suggested that his victory against Gatlin was more about his personal triumph following an injury-ravaged season.

"For me I understand why but I wanted to do it for myself also," he told BBC Sport. "It was a big deal.

"This means a lot because I've been struggling all season, it's taken me a while to work things out. It's been up and down but it's okay now."

Bolt has now claimed 15 gold medals at World Championships.