Geraint Thomas has abandoned the Giro d'Italia after suffering a pelvis fracture in a crash prior to the start of stage three.
Team INEOS rider Thomas was the pre-race favourite for the maglia rosa but fell on his left side after riding over a drinks bottle in the neutral zone on Monday.
The 2018 Tour de France champion returned to the bunch but was dropped by the peloton ahead of the ascent of Mount Etna, a 19-kilometre climb to the finish line.
Thomas finished over 12 minutes behind stage winner Jonathan Caicedo and lost more than 11 minutes to some of his general classification rivals.
Examinations carried out prior to stage four showed Thomas had sustained a fracture to his pelvis and would not contest the rest of the race.
"Geraint Thomas has been withdrawn from the Giro d'Italia ahead of stage four after further scans revealed a fracture of his pelvis following yesterday's crash," his team tweeted on Tuesday.
Thomas' team-mate Filippo Ganna dropped back to help guide him to the finish line and consequently relinquished the maglia rosa to Joao Almeida.