Kuss took the win as he eventually made his way out of a massive breakaway group to finish with a time of 4hour 27min 29sec.

The result saw him shoot up the general classification standings  to go eight seconds behind Martinez who deposed UAE Team Emirates rider Remco Evenepoel from pole position, with the Belgian now 2:47 off the pace.

"It was an incredibly hard stage and we wanted to try and go in the break," Kuss said following the 181.3-kilometre ride from Morella to Observatorio Astrofísico de Javalambre.

"The whole day I felt super good and was just thinking about when to go and when to try to make the difference.

"The whole climb I was just enjoying the environment we have in the Vuelta, it's always a special race for me. 

"For me, to win a stage is just incredible.

"I'm in the general [classification] now, so one day at a time."

A frantic start to the stage saw Evenepoel's Soudal Quick-Step let the group of 40 riders go up the road including the likes of Kuss, Team Bahrain Victorious' Dutchman Wout Poels, and Spanish red jersey contender Marc Soler of UAE Team Emirates.

The breakaway opened up a lead of six minutes before Kuss went solo at the beginning of the final climb.

With 2.5km remaining, the 28-year-old powered to the finish to take the win in what has made Team Jumbo-Visma even more of a threat.

The Dutch outfit now have three genuine contenders for the general classification which gives them another angle to attack from in future race strategy in Spain.

Both Slovenian Primož Roglič of Team Jumbo-Visma, who has won the Vuelta three times, and his teammate, two-time Tour de France champion Jonas Vingegaard of Denmark are in the mix.

The race is set to continue tomorrow with a 188.8km flat stage from Utiel to Oliva.