The 27-year-old, riding for Garmin-Sharp, appeared to slip on a manhole cover, taking out several Garmin-Sharp teammates, as wet conditions plagued the team time-trial.

The fall will come as a major blow to the nephew of Giro d'Italia and Tour de France winner Stephen Roche who had made this race the focus of his season.

Following the incident, Garmin-Sharp posted an official statement on their facebook page confirming Martin's injury and detailing the circumstances of his three fallen teammates.

"As you may have already seen, a crash in stage one of the Giro d'Italia today saw four Garmin-Sharp riders hit the ground," the statement read.

"Andre Cardoso, Koldo Fernandez, Nathan Haas, and team co-leader Dan Martin all sustained injuries of varying degrees.

"Dan Martin was transported immediately from the site of the crash to a local hospital where doctors confirmed a broken clavicle.

"He continues to be evaluated for additional injuries.

"Koldo Fernandez fought to the finish but was transported to a local hospital where doctors confirmed a broken clavicle.

"Andre Cardoso and Nathan Haas suffered contusions and abrasions and will be evaluated further tonight by team medical staff."

Svein Tuft of Orica GreenEdge was the winner of the team time trial, gifting him the pink jersey for tomorrow's second stage ©Getty Images



The time-trial was eventually won by Australia's Orica GreenEdge with Canada's birthday boy Svein Tuft, who turned 37, taking the leaders' pink jersey.

Colombia's Rigoberto Uran and Australia's Cadel Evans fared best of the pre-race favourites, with their teams, Omega Pharma-Quick Step and BMC Racing Team, second and third respectively.

This was just the 11th time the Giro has started outside Italy, and the first time the race has started outside continental Europe.

Sporadic rain and a damp road made conditions extremely tricky on the 21.7 kilometre route around the Northern Irish capital with Martin falling on a seemingly harmless straight section of the road.

Although the crash left Garmin-Sharp's race plans in tatters, they were still able to get five riders to the line together, the minimum required in the team time trial.

Despite this, the team finished three and a half minutes down on Orica GreenEdge's time of 24min 42sec, surely eliminating Canada's 2012 winner Ryder Hesjedal from contention too.

The second stage of the race is due to start and end in Belfast, after visiting the Giant's Causeway.

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