The 21-year-old had enough speed to sprint down the centre of the road to keep his rivals out of the way during the route from La Pobla de Segur to Vilanova i la Geltrú. 

Vernon got his first World Tour victory ahead of German Phil Bauhaus and Dorian Godon of France, who finished second and third, respectively.

"It’s brilliant," said Vernon. 

"We weren’t too far off on stage two [when he finished fourth], and I knew what I had to do to correct it. 

"We did it today, and it worked perfectly."

Portuguese João Almeida managed to finish third in the late intermediate sprint and continues to lead the overall standings followed by Nairo Quintana of Colombia.

Quintana was just one second behind Almeida, with compatriot Sergio Higuita third at seven seconds.

Vernon managed to cross the line in 5 hours, 21 min, 17sec. 

Australia’s Michael Matthews earned victory on the opening stage of the competition while his compatriot Kaden Groves sprinted to his first career victory on stage two. 

Ben O'Connor of Australia won stage three and Almeida triumphed on stage four of the 166.7 km climbing route from La Seu d'Urgell to Boí Taüll.

The sixth and penultimate stage will see the riders complete a 168,5 km route from Salou to Cambrils.