The USA brought the curtain down on a memorable 12th IAAF World Championshis In Athletics by blitzing to a predicted gold medal in a world leading 2:57.86.
In a race shorn of Olympic silver medallists Bahamas, who were disqualified in yesterday's heats, the USA won at a canter with a team boasting the combined talents of the World individual 400m gold and silver medallists - LaShawn Merritt and Jeremy Wariner as well as the reigning World and Olympic 400m hurdles champions Kerron Clement and Angelo Taylor, respectively.
Great Britain edged a battle with their 'old enemy' Australia to take the silver medal in 3:00.53 - their first global medal in the men's 4x400m for 12 years.
The Australian quartet hung on for bronze 0.37 adrift to claim their first ever World Championships medal in this event - but, really, this was all about the USA. Taylor gave the USA a solid, though far from specatuclar start with Arismendy Peguero of the Dominican Republic and Great Britain's Conrad Williams also enjoying prominent first leg runs.
When the stagger unwound on the back straight of the second leg Wariner held a slight lead with the Domincan Republic, Australia, Great Britain and Poland all in close order.
It was on this second leg when the USA stamped their authority on the race. Wariner, who had disappointed in the individual 400m, ran like a man possessed and handed the baton on to World 400m hurdles champion Kerron Clement with a ten metre lead. Wariner had posted a scintillating leg of 43.68.
In the scrap for the minor medals World individual 400m finalist Michael Bingham of Great Britain had established a clear gap on the remainder of the field with Australia courtesy of Ben Offereins in third.
Clement then proceeded to further extend the USA's advantage with a 44.76 penultimate leg but there was interesting development behind.
Australia's Tristan Thomas blasted past Great Britain's Rob Tobin down the back stretch to take second spot.
However, Tobin used his superior relay experience to burst past the Aussie 400m hurdles specialist down the home straight.
Clement handed the baton to the Olympic 400m champion LaShawn Merritt with at least a 15m lead. Great Britain with Martyn Rooney running anchor took the baton three metres clear of Australia.
Merritt ran a controlled anchor leg of 44.15 to help USA cruise to their sixth World Championships men's 4x400m gold and third in succession.
Meanwhile Australia's fourth leg runner Sean Wroe had closed the gap and was in striking distance of Rooney, before the tall Brit responded to the challenge to kick clear and secure the silver. The Australians had the consolation of bronze.
The Belgian quartet can be proud of their efforts to earn fourth spot in 3:01.88 with Poland fifth in 3:02.23. Completing the picture were the Domincan Republic (3:02.47), France seventh in 3:02.65 and Nigeria eighth in 3:02.73.
Steve Landells for the IAAF