Wariner coasts through

Wariner has been on fire this season, improving his personal best to 43.50 seconds at the Stockholm Grand Prix with his next milestone Michael Johnson's world record of 43.18 set at the 1999 world championships in Spain.

He has suggested it could fall here, but was in no mood to talk about it.

"I feel good, I am fine," he said after running 45.10 in his heat, pulling back almost to a walk before crossing the line.

"Of course, it is the world championships and I shut it down at 250 metres. The weather conditions here are nothing for me, I train like this every day.

"The track is good but I do not want to talk about the world record now."

The fastest through the heats was Chris Brown from Bahamas in 44.50.

One man who considers he has the beating of Wariner is his compatriot, LaShawn Merritt, who said he will do all he can to upstage him.

"In the final, I am going to be ion the battle for the gold medal, not only in the battle for the silver and bronze medal."