The Spaniard, who started the day fourth overall, attacked with more than 40km remaining on the category-2 Puerto El Colloa, drawing out the likes of Richard Carapaz (Ineos Grenadiers) as they tried to put leader Primož Roglič (Jumbo-Visma) on the back foot.
However, as he followed Carapaz around a right-hand bend on a flatter section of the climb, Valverde appeared to hit a pothole, lost hold of his handlebars, slipped out at speed and hit the tarmac.
He slid to the side of the road and onto a patch of gravel, heading a through a gap in the metal barriers to the lip of the hillside. Fortunately, he did not fall far.
Valverde clambered back to the road, with the help of Jose Joaquín Rojas, who had set up his attack, and stood up with right arm bloodied and jersey dusty and torn.
He was offered a new bike by a Movistar mechanic but he refused it, and went on to clutch his right shoulder. After consolation with doctors and team staff, he did remount and continue the stage for a short time. However, he had to be pushed by teammates, and it was clear his time at the Vuelta had come to an end.
He climbed off the bike and appeared to break down in tears as he hugged his team director.
The Movistar team initially announced that Valverde had not suffered any fractures but late on Friday further examinations on his right shoulder and hip confirmed a collarbone fracture. The team said Valverde will undergo an operation in Murcia on Saturday.
Valverde started the day fourth overall, 41 seconds down on Roglič. His Movistar teammates Enric Mas and Miguel Angel López occupied second and third on the GC, and the Spanish squad had looked to use that advantageous position from range on stage 7.
However, it soon came crashing down and Valverde was forced to bid an emotional farewell to his home Grand Tour, which has brought him so much success in the past.
Deputy Editor - Europe. Patrick joined Cyclingnews after a work experience stint in 2015 and hasn't left. Prior to that, he studied French and Spanish at university and went on to train as a journalist. Rides his bike to work but more comfortable on a football pitch.
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