Caleb Ewan celebrated the biggest win of his career on Wednesday, the 21-year-old Australian claiming the fifth stage of Spain's Vuelta with Dutch rider Tom Dumoulin the new overall leader.

Ewan, tackling his debut Vuelta, prevailed in a dash for the line after a 167.5 kilometre ride from Rota to Alcala de Guadaira.

His teammate, Johan Esteban Chaves, started the day in possession of the leader's red jersey but by the end of the stage he'd been relegated to second in the general classification, albeit by only one second to Team Giant-Alpecin's Dumoulin.

Dumoulin came in 15th with Chaves in 20th in the stage.

In third, 16sec back, was Team Sky's Irish rider Nicolas Roche.

Ewan's win was made all the sweeter as he crossed the line with specialist sprinters John Degenkolb of Germany - whose big race wins include the Milan-SanRemo and Paris-Roubaix - and Slovakia's Peter Sagan - a four time winner of the Tour de France points classification - in his wake.

Ewan was set up for his breakthrough success in perfect style by other members of his team in the final 50 metres.

"This is by far the best day of my career," he smiled.

"To beat some of the top sprinters in the world, especially riders like Degenkolb or Sagan, on a climbing finish like that, that means a lot to me."

Ewan, for whom this is a first shot at one of the Grand Tours, added: "It's an honour to compete against riders like that."

Sagan was well placed in second but he was put in his place by the promising Aussie who came round the German to take the honours.

Thursday's sixth stage is a 200.3km ride from Cordoba and Siera de Cazorla with a finish on a third category summit.

Source: AFP