Former Paris-Nice champion, Luis Leon Sanchez, has been forced to withdraw from the Tour de France following a devastating crash that resulted in a broken collarbone.

The Spanish rider was entangled in one of the numerous accidents that marred the climactic moments of the race's fourth stage.

Sanchez's team, Astana Qazaqstan, has confirmed that he will return home on Wednesday for surgery.

Reflecting on the incident, Sanchez expressed the rapidity of events in the frenetic finale, where multiple twists and turns proved treacherous. "I had no control over my bike on that tricky surface," he lamented.

The loss of Sanchez deals a significant blow to the aspirations of his teammate, Mark Cavendish, who seeks to add another mass sprint victory to his remarkable collection.

Cavendish currently shares the all-time record of 34 stage wins with cycling legend Eddy Merckx.

Sanchez's absence will be keenly felt, especially in stages where he played a pivotal role in leading out Cavendish.

As the Tour progresses, Wednesday's fifth stage looms as the first true mountain challenge of this year's edition.

The terrain is expected to shake up the general classification, with defending champion Jonas Vingegaard and two-time winner Tadej Pogacar primed to test each other's mettle in the Pyrenees.

The daunting 162.7-kilometer (100.9-mile) route includes a grueling 15.2-kilometer ascent up the formidable Col de Soudet, renowned for its highest category rating.