Ballan's victory delighted the home fans in Varese, Italy
Italy's Alessandro Ballan produced a stunning burst to win the road race title at the World Championships.
Ballan sprinted away from a breakaway group on the final lap in Varese to win by three seconds from team-mate Damiano Cunego and Denmark's Matti Breschel.
Fellow Italian Paolo Bettini, who was chasing an unprecedented third victory on the trot, finished down the field in his final race before retiring.
Russell Downing (49th) was the only one of a six-strong British side to finish.
The Rotherham rider came home alongside Bettini, who punched the air in delight when news filtered though to him of Ballan's win.
It was a fitting victory for Ballan, who had covered numerous breakaways and shown great team loyalty during much of the race.
He said: "In the last couple of kilometres the people screaming pushed me on.
"The public was fantastic. I've never cycled in conditions like this. I was tired and didn't think I was going to make it because I had cramps.
"I still can't believe it. This is something special," he added.
Ballan's victory gave Italy a 19th world road race title and means the coveted rainbow jersey will be worn by an Italian for the third consecutive year.
Venezuela's Richard Ochoa Quintero, Ukraine's Oleg Chuzhda and Luxembourg's Christian Poos were the first riders to make a significant move during the second lap of the 15-lap 260km race and they quickly opened up a lead of over two minutes.
The gap was allowed to stretch beyond 17 minutes before the peloton, led by the Italians, began to reel them in, but they dropped the pace at the end of the seventh lap.
Towards the end of lap eight, with nobody else wanting to take on the workload, the Italians sent Marzio Bruseghin to the head of the chasing pack and he almost single-handedly dragged the peloton to within 11 minutes.
With laps running out, the breakaway trio were swallowed up and Ballan went straight onto the attack to try and set up a platform for Bettini.
But with attacks coming from everywhere, it proved difficult for any one team to take control of the race.
Ballan continued to cover breakaway attempts and was in a leading group of six as the final lap started.
Still the attacks came as Austria's Christian Pfannberger, Dutchman Robert Gesink, Breschel all made a bid for glory.
But Italian trio Ballan, Cunego and Davide Rebellin were dictating tactics.
And with a little over two kilometres remaining, Ballan shot down the blind side and quickly opened up an advantage that Cunego and Rebellin were not about to allow anyone to close.
Bettini received a reception almost as raucous as his team-mate Ballan when he finished nearly five minutes later.
The two-time world champion, who announced his retirement on Saturday, said: "We showed on our home turf in front of our fans what a team we have.
"The whole pack thought I was going to win and nobody gave me space, but what is important is that an Italian won.
"Ballan doesn't win often, but when he does he makes it big. I'm proud to conclude my career with a national team like this."
Downing led the British contingent, with team-mates David Millar, Chris Froome, Stephen Cummings, Geraint Thomas and Ian Stannard all failing to finish.
Men's road race result
1. Alessandro Ballan (Ita) 6hrs 37mins 30secs
2. Damiano Cunego (Ita) +3 secs
3. Matti Breschel (Den) same time
4. Davide Rebellin (Ita) same time
5. Andriy Grivko (Ukr) same time
6, Joaquin Rodriguez (Spa) same time
7. Fabian Wegmann (Ger) same time
8. Christian Pfannberger (Aut) same time
9. Nick Nuyens (Bel) same time
10. Robert Gesink (Ned) same time
49. Russell Downing (GBR) +4:53"
David Millar (GBR) DNF
Chris Froome (GBR) DNF
Stephen Cummings (GBR) DNF
Geraint Thomas (GBR) DNF
Ian Stannard (GBR) DNF