Sagan (SVK) pounced on the penultimate climb of the day and was able to carry that effort to finish solo ahead of Australia's Michael Matthews and Ramunas Navardauskas of Lithuania.
His victory came after a season littered with second and third places and 261.4km of racing on the technical and inner-city road circuit which featured repeated climbs up 200m of cobbles in Libby Hill Park.
Peter Sagan, pro cycling's Mr Personality @richmond2015 #sbscycling http://t.co/IxYClLkY7p — CyclingCentral (@CyclingCentral) September 27, 2015
Zdenek Stybar (CZE) jumped first with John Degenkolb (GER) and Greg van Avermaet (Bel) covering. A select group dragged themselves up toward the trio before 23rd Street and it was there that Sagan made his bold attempt to sieze the championship.
He first created a slight gap on the peloton and extended it further on the next two climbs before completely emptying the tank on the 680m drag to the finish.
Peter Sagan @richmond2015 interview #sbscycling http://t.co/UqDI0nSYyo — CyclingCentral (@CyclingCentral) September 27, 2015
Matthews won the bunch sprint for silver ahead of Navardauskas while Australian team-mate Simon Gerrans finished closely behind in sixth.
“I was about fifth or sixth wheel when Sagan went,” Matthews said. “There were two guys between me and the three that got away dropped the wheel. I thought some other guys would chase to close it, but they didn’t.
“There were still three kilometres to go and such a hard finale. I didn’t think he’d have enough legs to get to the finish, but I obviously underestimated him.”
Australia played a patient game througout the race in working to deliver Matthews on to the podium. The team appeared happy to let the Dutch, Germans and Spaniards do the work chasing the breaks and keeping the race tempo high and did not show themselves until near the finish.
“Today was a massive day,” elite men’s national road coach Brad McGee said. “It was a huge day for cycling and an incredible day for Australia. I don’t think a World Championship has ever been so exciting in my memory.
“As Australians, we have to pinch ourselves and realise that there is a silver medal here for a 25-year-old who showed great form and composure in a quite difficult day in the end – a lot more difficult than most people were thinking.”
“I’m proud of how the boys orchestrated today. All of them rose to the occasion, and in many cases, they rode above themselves. The guys gelled well and stuck to the game plan.”
The race started fast as eight riders made the break before proceedings settled into the familiar pattern usually seen in professional cycling.
The men's elite road race podium (Supplied) Source: Supplied
Containing Ted King (USA), Ivan Stevic (SRB), Sung Baek Park(KOR), Carlos Alzate(COL), Jesse Sergent(NZL), Sergei Tvetcov (ROU), Conor Dunne(IRL), Andriy Khripta (UKR) the selection held a lead that went past 3min 30sec before the Dutch led peloton inched in back to half that.
With less than 120km to go the break lost Park, Khripta and then Stevic even as the peloton kept tempo with the race under its firm control.
Twenty-five kilometres later the shape of the race changed when the break was swept up by a peloton determined to force a selection that would eliminate the sprinters.
After some further chopping and changing and failed attempts to escape, a four-man selection including American Taylor Phinney was allowed some freedom. Sharing the effort was Jarlinson Pantano (COL), Kanstantsin Siutsou (BLR) and Guillaume Boivin (CAN).
Pantano soon lost touch but the remaining trio hammered the break to grow its lead to almost two minutes as a large crash slowed and split the chasers.
The Phinney led trio were finally picked up as the race entered its final two laps in and around Richmond and was quickly replaced by a seven-rider group representing several of the major nations, Netherlands (Bauke Mollema) Spain (Daniel Moreno), Italy (Elia Viviani), Great Britain (Ian Stannard), Belgium (Tom Boonen) the 2014 world champion Michal Kwiakowski (POL) and Andrey Amador of Costa Rica.
On seeing that powerhouse group escape, Germany's Andre Greipel set the rapidly depleting peloton in chase with a hard turn at the front which chipped away at the narrow time gap, forcing the catch at 20km.
The was sustained pressure on the peloton from that point with repeated surges and attacks but none stuck until Sagan made his winning move in the dying kilometres of the race.
