Portugal's Rui Costa kept his composure in a tense finale to upset the favourites and clinch the Road World Championships men's elite road race on Sunday.

Costa made his move some 1.5km from the finish to bridge the gap with Joaquim Rodriguez and beat the Spaniard in a sprint finish.

Another Spaniard, Alejandro Valverde, took third place for his fifth podium at the event although he has never won the coveted rainbow jersey.

Home favourite Vincenzo Nibali, who launched the decisive attack in the Fiesole climb despite crashing earlier in the 272.3km race, had to settle for fourth.

The move left one-day race specialists Fabian Cancellara of Switzerland, Peter Sagan of Slovakia and defending champion Philippe Gilbert of Belgium stuck on the tarmac on the final of ten laps on a 16.6km circuit.

About half of the peloton had already abandoned midway through the race, and the highly fancied British team had gone out with five laps to go on an woeful day for Tour de France champion Chris Froome and his team-mates Bradley Wiggins, Mark Cavendish and Geraint Thomas.

The Irish team shared a similar fate to their geographical neighbours with their quartet of Dan Martin, Matt Brammeier, Sam Bennett and Nicolas Roche all failing to finish the race.

Only 61 riders of the 208 on the start list finished the rain-hit race that almost turned into carnage.

Multiple crashes and the Italian team's pace at the front caused splits in the skinny peloton but Sagan, Cancellara and Gilbert held on until Nibali attacked and was followed by Rodriguez, Valverde, Costa and Colombia's Rigoberto Uran, who was ruled out of contention when he crashed in a descent.

Former world champion Cadel Evans of Australia, and American Vuelta winner Chris Horner pulled out after being involved in crashes.