In 2004 Asafa Powell wins his Olympic semi with the fastest time of the two heats.
He goes on to get 5th in the final.
Asafa Powell set the WR in 2005 at 9.77 and had the three fastest times in the world that year but was hurt and did not race at WC's that year.
He tied that WR twice in 2006.
Asafa Powell set the world record again in 2007 with a 9.74. Plus ran 9.78 twice again giving him the three fastest times.
He won every race that year except for WC's.
Tyson Gay's best that year was 9.84 (.10 slower than Powell)
Powell's Bronze that year was a big choke.
In 2008, Powell improves his PR to 9.72, 2nd fastest time on the year behind Bolt.
But he finished 5th at the Olympics.
Powell got Bronze behind Bolt and Gay in 2009. That was his best performance.
2011 - Powell had the second fastest time in the world at 9.78 and won several races. But he was injured and did not run at WC's. No medal.
2012 - Powell had the 5th fastest time in the world and finished 8th at the Olympics, pulling up lame.
And this summer he had the 5th fastest time of the year but was pulled form the World team with a positive test.
So, When did Powell not perform when it mattered most?
Every time he could.