Gerald Ciolek (MTN-Qhubeka) out-gunned pre-race favourite Peter Sagan (Cannondale Pro Cycling) to win a snow-disrupted edition of Milan-San Remo that will live long in the memory.

Race officials were forced to shorten the first Monument of the season after 117km of racing after heavy snow on the Passo del Turchino made the climb unrideable. Riders returned to their team buses to bypass the ascent and the race eventually restarted on the coast with 130km to San Remo.

A six-man break went away early in the day but the escapees were caught with 30km remaining, teeing up a thrilling finale which eventually saw Ciolek win ahead of Sagan and Fabian Cancellara (Radioshack-Leopard-Trek) from a six-way sprint to secure the first-ever WorldTour victory for an African-registered team.

British national champion Ian Stannard (Team Sky) finished sixth after launching a series of brave attacks in the final kilometres, while Mark Cavendish (Omega Pharma-QuickStep) crossed the line in ninth.

Bad weather was forecast in the build-up to the race but few could have predicted the severity of the disruption it would cause.

Filippo Fortin (Bardiani Valvole), Matteo Montaguti (Ag2r La Mondiale), Diego Rosa (Androni Giocatto), Maxim Belkov (Katusha), Lars Bak (Lotto-Belisol) and Pablo Lastras (Movistar) formed the early break and opened up a lead of more than ten minutes after just 40km of racing.

But, with rumours circulating that the Turchino section of the race was to be neutralised, Sagan’s Cannondale team and Vincenzo Nibali’s Astana squad set about reducing the deficit to seven minutes and ten seconds by the race was called to a halt after 117km.

A host of frozen and snow-covered riders then took to Twitter during an enforced interval which lasted nearly two hours to post pictures of the damage inflicted by the weather.

The race was eventually restarted from the coastal town of Cogeleto, and the remainder of the course was also re-routed to miss the selective climb of Le Manie, reducing the total distance of the longest one-day race of the season from 298km to 244km.

The six breakaway riders were allowed to regain their lead before the peloton rolled out of Cogeleto to set about catching the escapees, although a number of riders, including Omega Pharma-QuickStep’s Tom Boonen, did not emerge from the team buses for the restart.

Team Sky led the chase but Geraint Thomas was one of a number of riders to hit the deck in a crash, along with Garmin-Sharp sprinter Tyler Farrar, while Edvald Boasson Hagen cracked on the Cipressa, by which time the breakaway had been reeled in.

Philippe Gilbert (BMC Racing) then attacked on the descent of the Cipressa and the world champion was joined by Stannard, Sylvain Chavanel (Omega Pharma-QuickStep) and Russian national champion Eduard Vorganov (Katusha).

Gilbert was first to return to the peloton, while Vorganov was dropped on the Poggio, the final climb of the race, leaving Stannard and Chavanel out alone. The 25-year-old Stannard put in a succession of huge digs on the climb and led the race over the summit with Chavanel on his wheel and the peloton nearly 30 seconds adrift.

That prompted Ciolek, Sagan, Cancellara and Luca Paolini (Katusha) to use the descent to bridge the gap, catching the the leaders with just three kilometres remaining.

Sagan then attacked with two kilometres to the line but was soon caught before Stannard made a move of his own, only for his brave solo bid for glory to end under the flamme rouge.

And, with the lead six together going into the sprint, it was left to German fast man Ciolek to upset the odds and claim the biggest win of his career.

Milan-San Remo 2013 – result

1) Gerald Ciolek (GER) – MTN-Qhubeka – 5:37:20 hours
2) Peter Sagan (SVK) – Cannondale Pro Cycling – same time
3 Fabian Cancellara (SWI) – Radioshack-Leopard-Trek
4) Sylvain Chavanel (FRA) – Omega Pharma-QuickStep
5) Luca Paolini (ITA) – Katusha
6) Ian Stannard (GBR) – Team Sky
7) Taylor Phinney (USA) – BMC Racing
8) Alexander Kristoff (NOR) – Katusha +14″
9) Mark Cavendish (GBR) – OmegaPharma-QuickStep – same time
10) Bernhard Eisel (AUT) – Team Sky