American Allyson Felix discusses winning her 400m heat in 50.60 seconds at the World Championships in Beijing, China.

Script: SOUNDBITE (English) Allyson Felix, USA 400m

"Yeah. It felt like I controlled it and in a comfortable manner so that's what I wanted to do."

Q. You got to slow down. Have you got enough in the tank for what else you need to do?

"Yeah. I am feeling really fit right now. So I think I will be good."

Q. Finally, just on last night. A two-three for the United States.

"Yeah. That was an exciting one. I think we all wanted to see a close race like that so it was fun."

Q. Do you think it was one of the most exciting 100m races for a few years?

"Yeah. I think we haven't seen anything that close in some time so that was a fun one."