The IAAF will send a warning to the American sprinter for disrupting this year's World championships but will take no further action.
Three-time world champion Maurice Greene remained on course for an unprecedented fourth successive 100m title. Tim Montgomery also qualified for the semis easily.
American sprinter Tyson Gay's former coach has been suspended for eight years for doping violations, the US Anti-Doping Agency said on Wednesday.
Bernard Williams upset world record holder Tim Montgomery to claim a stunning win in the men's 100 metres at the U.S. championships.
Gay's reduced ban sends wrong message, says Bolt.
Sprint legend Carl Lewis on Thursday waded through the Tyson Gay doping controversy, saying that the reigning Olympic 100m and 200m champion Usain Bolt has raised a legitimate issue but he should 'clean up his own country first' before talking about others.
