Usain Bolt continues to rule the sprinting world

It is a mark of Usain Bolt's talent that after winning yet another world title here in Moscow he seemed almost disappointed with his performance.

The time of 9.77 seconds was slow by his exceptional standards and some way off his world record of 9.58secs set in Berlin four years ago.

But on a night when electric storms provided the spectacular backdrop to another world-beating performance, he still showed why he is the sport's biggest draw.

The final was missing some of the world's fastest men. No Asafa Powell and no Tyson Gay - both forced to pull out after testing positive for banned drugs. And no defending champion Yohan Blake after injury ruled out Bolt's Jamaican understudy.

So it was left to 2004 Olympic champion Justin Gatlin to provide the biggest threat. After a build-up to these championships dominated by doping controversies, the last thing the International Association of Athletics Federations would have wanted was a win for an American who served a four-year ban for drugs.

In the end Bolt was too good for Gatlin, and too good for anyone else for that matter.

There were still too many empty seats in the Luzhniki Stadium on Sunday night but it was far better than the opening evening - a reflection of how Bolt sells tickets like no other athlete.

But how much longer can the sport rely on him to deliver the marquee moments?

He will be 27 later this month and 29 by the time the Rio Olympics come around. Perhaps it's less a question of age, more one of motivation.

He shows no signs of losing interest. The Olympic 'treble-treble' is his stated aim but another world record in the 100m or 200m can't be ruled out.

We have become so used to seeing Bolt do extraordinary things that it is easy to take it for granted. We shouldn't. Before we know it he will be gone and athletics will be left with an impossible hole to fill.