Cadel Evans became Australia's first ever world road race champion thanks to a stunning late assault in Switzerland.
He rode away from Russia's Alexandr Kolobnev and Spain's Joaquin Rodriguez on the last climb to win by 27 seconds.
World time trial champion Fabian Cancellara produced an aggressive ride on home soil at Mendrisio but had to settle for fifth place.
It was a race to forget for Britain's riders with Steven Cummings the top-placed at 52nd in the standings.
Riding on a course which was not to their strengths, the Great Britain riders failed to make much of an impression with Roger Hammond, back in 92nd, the next GB rider over the finish line.
And their GB team-mates Christopher Froome, Daniel Lloyd, Ben Swift, Geraint Thomas, David Millar, Ian Stannard and Russell Downing all failed to complete the course.
The course suited me - Evans
Millar crashed early in the race to ruin his chances of success.
"The team was riding excellently, that's what is gutting about it," said a frustrated Millar.
But it was a different story for Evans, as he threw off his reputation as a nearly man on the world championship stage in spectacular fashion.
"[This] is an answer to those criticisms that I've had, saying I never attack," Evans said.
Evans lives only three miles away from Mendrisio and always believed the course provided him with a better chance of becoming world champion than the 2010 course in Geelong, Australia, where he lives for three months of the year.
"This course suits me better than the one in Geelong and I think I proved that today," he added.
The 262km (163-mile) race was around 19 laps of a course in the south of Switzerland, just a few miles from the Italian border.
Entering the penultimate lap, a leading group of about 25 riders was one minute 20 seconds clear of the peloton.
However, as the leaders descended the Acquafresca climb Cancellara came flying past, having jumped across the gap from the peloton.
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The Swiss powerhouse settled into the group and countered every attack, including a solo bid from Alexandre Vinokourov, before splintering the group coming down the Acquafresca descent for the final time.
However, the leaders came together once more and the decisive move came from Evans on the final Novazzano climb.
With Cancellara trying to bide his time Evans went for home and by the time the Swiss star made his move it was too late to haul Evans back.
Cancellara launched a late attack of his own but just failed to ride down Kolobnev and Rodriguez, with Spain's Olympic champion Samuel Sanchez pipping him on the line for fourth.
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