Australian youngster Caleb Ewan surprised some of the more seasoned sprinters by surging to victory in the fifth stage of the Vuelta a Espana on Wednesday as his Orica team mate Esteban Chaves lost the overall lead to Tom Dumoulin.

Ewan beat German John Degenkolb (Giant) to the line in the 167.3-kilometre stretch to Alcala de Guadaira, with Peter Sagan of Slovakia (Tinkoff-Saxo) third and Luxembourg's Jempy Druecker (BMC Racing) fourth.

Dumoulin (Giant) leads the general classification going into tomorrow's sixth stage to Sierra de Cazorla by one second from Colombian Chaves, with cousins Nicolas Roche (Team Sky) and Daniel Martin (Cannondale) 16 and 27 seconds down in third and fourth respectively.

Roche finished today’s stage in 22nd place, while Martin’s 27th place finshed saw him drop two seconds on Roche, but he holds on to fourth place overall.

Martin is just six seconds ahead of Spain's Antonio Valverde (Movistar), one of the favourites for overall victory.

Speaking after his win, Ewan said "it's an incredible feeling, this is by far the biggest victory of my career".

"It means a lot to me to beat two of the best sprinters in the world and that finish really suited them and they're strong," the 21-year-old Sydney native added.

"I knew it would be tough to beat them but I felt good and my team did an awesome job and delivered me perfectly. When I crossed the line there was so much emotion, I was so happy."

Sky leader Chris Froome, who won a second Tour de France crown in July and is bidding for a rare Tour-Vuelta double, finished 12th and moved up to seventh overall, 35 seconds off the lead.

The Briton is bunched with some of his main rivals including Spaniards Valverde and Joaquim Rodriguez (Katusha, +36), Valverde's Colombian team mate Nairo Quintana (+39) and Italian Fabio Aru (Astana, +52).