American rider Ben King sprinted away from breakaway partner Nikita Stanlov to win the fourth stage of the Vuelta a Espana on Tuesday as Michal Kwiatkowski hung onto the overall lead.
King of Dimension Data and Kazakh rider Stanlov of Astana were part of an early nine-man breakaway which built a gap of almost 10 minutes as Kwiatkowski's Sky team set a gentle pace in the peloton.
By the first summit finish of this year's race, a category one climb to Alfacar, King and Stanlov were alone. The American surged away with a frantic 100-metre sprint to win the 161.4-kilometre stage starting in Velez-Malaga by two seconds.
"It was a dream. For me personally, I'm still in shock," the 29-year-old King told Eurosport immediately after his first stage victory in a major tour. "That was an objective at the start of the year."
French climber Pierre Rolland (EF-Education First) was third, 13 seconds back.
On the final climb, Briton Simon Yates of Mitchelton Scott and German Emanuel Buchmann of Bora-Handsgrohe broke away from the main pack to cut 25 seconds out of Kwiatkowski's lead.
The Pole leads Buchmann by seven seconds, Yates by 10 and Spaniard Alejandro Valverde of Movistar by 13.
Wednesday's fifth stage is a 188.7km run mostly along the Mediterranean coast from Grenada to Roquetas de Mar with one category 2 to potentially break up the peloton and prevent a sprint finish.