Caleb Ewan claimed the win on stage five of the Giro d'Italia today ©Getty Images

Australian Caleb Ewan secured a sprint victory on a chaotic fifth stage of the Giro d'Italia.

The Lotto Soudal rider was fastest to the line, outsprinting Italians Giacomo Nizzolo and Elia Viviani - respectively of Team Qhubeka Assos and Cofidis - who completed the podium.

Spain's Mikel Landa did not complete the stage following a fall and is out of the race, and Russian Pavel Sivakov also came off the bike and there are fears that his Grand Tour could be over.

As the riders followed a 177-kilometre course from Modena to Cattolica, Sivakov's title hopes came crashing down as the Ineos Grenadiers rider hit the ground hard with just 15km to go - seemingly touching wheels with a team mate.

Despite suffering cuts to his right leg and arm, Sivakov got up, changed bikes and competed the stage, but was too far behind the peloton to have a chance of staying in contention and finished more than 13 minutes behind the winner.

In the final kilometres, Bahrain Victorious rider Landa was a victim of a crash out of his control. 

Joe Dombrowski of the United States - yesterday's stage winner - clipped a signalman and fell, taking the Spaniard with him. 

Although Dombrowski got back up to finish more than eight minutes behind the leader, Landa stayed down and needed medical attention.

Bahrain Victorious team boss Franco Pellizotti indicated that Landa may have a fractured collarbone or wrist.

In the late sprint, Ewan nearly went down in a tangle with Belgium's Tim Merlier of Alpecin-Fenix, but managed to stay up and overtake Nizzolo in the final 50 metres.

Slovenian veteran Peter Sagan of Bora-Hansgrohe and Colombian rider Fernando Gaviria of UAE Team Emirates completed the top five.

In the general classification, Italian Alessandro De Marchi of Israel Start-Up Nation now has a 42-second gap to second-placed Louis Vervaeke of Belgium and Alpecin-Fenix.

Portugal's Nelson Oliveira of Movistar has moved up to third, 48 seconds adrift of the race leader.

Sivakov has withdrawn from the race.

The first mountain stage of this year's Giro awaits tomorrow.