Montgomery anchored the victory

American sprinting's strength in depth was underlined at the Penn Relays in Philadelphia.

The USA took a clean sweep of the medals, showing why they are favourites to take gold at the IAAF World Championships in Paris this summer.

The hosts won all of the six relay events, defeating strong sides from Africa, the Caribbean, Europe and Canada.

But it was their dominant performance in the 4x100m relay which delighted a crowd of almost 40,000 who turned out in cold conditions.

The Red team of Jon Drummond, Justin Gatlin, Coby Miller and world 100m record holder Tim Montgomery ran a fast time of 38.67 seconds.

Inexperienced

That held off the challenge of USA's Blue quartet, second in 38.67secs thanks to a fast last leg by JJ Johnson, with an Olympic development squad crossing the line third in 38.86.

Jamaica finished fourth in 39.13secs ahead of a relatively inexperienced British team.

The Britons - Jonathan Barbour, Julian Golding, Dwayne Grant and Mark Lewis-Francis - crossed the line in 39.59secs.

After his first race since breaking the world record in Paris, Montgomery said: "I'm back at it. I've got a bullseye on the back of my shirt now.

"It was challenging and everything I wanted - it was fun.

"This race lifted a lot off my shoulders. I wanted to lift this burden."