LONDON, ENGLAND - AUGUST 09: Usain Bolt of Jamaica celebrates as he crosses the finish line to win gold during the Men's 200m Final on Day 13 of the London 2012 Olympic Games at Olympic Stadium on August 9, 2012 in London, England. (Photo by Alex Livesey/Getty Images)

Barcelona – Former Olympic 100m champion Maurice Greene believes Usain Bolt will lower his own 100m world record of 9.58sec, which the Jamaican has held since the 2009 world championships in Berlin.

“I don't think we've yet seen the best Bolt, capable of being perfect from the start to the finish,” said Greene, who won the 100m at the 2000 Sydney Olympics and claimed bronze in Athens four years later.

Five-time world champion Greene, now retired, had backed Bolt's compatriot Yohan Blake to win the 100m at the London Olympics.

But 26-year-old Bolt successfully defended his three Olympic titles at 100m, 200m and 4x100m in the British capital.

Greene was speaking on the sidelines of the International Association of Athletics Federations (IAAF) centenary celebrations here. Sapa-AFP