Joaquin Rodriguez protects lead

LAGOS DE COVADONGA, Spain -- Joaquin Rodriguez withstood Alberto Contador's repeated attacks to successfully defend his overall lead in the Spanish Vuelta's 15th stage, won by Antonio Piedra of Caja Rural on Sunday.

Rodriguez stayed close to Contador's back wheel with every surge by his fellow Spaniard on the last special category climb to the finish line at the Lagos de Covadonga summit.

"Thank God there weren't any more kilometers to go because, if so, I wouldn't have made it," said Rodriguez, who rides for Katusha. "Fortunately, I had that little burst for the final 500 meters."

Despite protecting his lead by finishing in the same group as SaxoBank's Contador, Rodriguez said the former Vuelta winner was in fine form.

"(Contador) is all over me. He is in charge," said Rodriguez. "His attacks are top rate. I was amazed at his speed on the climb."

Piedra separated from a small breakaway group with just over 10 kilometers to go and finished the 116-mile stage in the Picos de Europa mountains in 5 hours, 1 minute, 23 seconds.

Ruben Perez of Euskadi-Euskaltel, Lloyd Mondory of Ag2r La Mondiale and Piedra's teammate David de la Fuente were next, just over two minutes behind the pacesetter.

Rodriguez, Contador and Movistar's Alejandro Valverde finished together 9:25 behind.

Rodriguez maintained his 22-second lead over Contador, and Valverde moved third in the overall classification at 1:41 back.

"I am not worried about Rodriguez," said Contador, who is competing in his first grand tour since completing a doping ban. "He is stronger than ever, but I am not going to win anything by not trying. You never know when a rider will have a bad day. I will fight until the last meter."

The biggest loser of the day was Christopher Froome of Team Sky.

The British rider could not stay with the other contenders and saw the gap between him and the red jersey grow to 2:16.

"It was a really tough climb today, I am really suffering," said Froome, runner-up both at the Tour de France and last year's Vuelta.

"I am just trying to do as much as I can every day," he said, adding that his chances of winning the Spanish classic are dwindling. "I am not sure where I am going to end up. I'll just do the maximum possible and I am happy with that."

On Monday, riders face a third straight mountain stage that is arguably the most demanding of the 21-stage race. The 114-mile stage starting from the city of Gijon takes riders through four category climbs and finishes at the Cuitunigru summit.

The race ends on Sept. 9 in Madrid.