Jamaican sprinter Usain Bolt wins the 100-meter race at the Diamond League meet in June in Oslo. (AFP/AFP VIA GETTY IMAGES)

Jamaica’s Usain Bolt won by such extraordinary margins at the 2008 Summer Games in Beijing and 2009 world championships in Berlin it looked as if he would never be challenged, let alone beaten. His grinning poses and premature celebrations gave him charisma that seemed to match his speed.

And then that speed just wasn’t there anymore.

Bolt enters the Games having lost a pair of races at Jamaica’s Olympic trials to training partner Yohan Blake. At the June trials in Kingston, Blake set a personal best in the 100 meters with his finish in 9.75 seconds. In an international grand prix last year, he dropped a 19.26 — second-fastest ever to Bolt’s world record 19.19.

Just four years after seemingly revolutionizing sprinting with his long legs and massive strides, Bolt looks a bit like old news.

After Bolt false-started at last year’s world championships, Blake won his first world title. After Jamaica’s trials, Bolt rested a hamstring that he tweaked during the 200, while Blake tuned up for London, easily winning a race in Lucerne, Switzerland, in 9.85.

Blake recently told the BBC that Bolt inspires him.

“He will say to me: ‘Yohan, look, you’re not doing this for the people, you’re not doing this for the fans, you’re not doing this for your family, you’re doing this for yourself,’ ” Blake said. “He can motivate me.”