MADRID (AFP) -- Chris Froome hailed his greatest athletic achievement after becoming just the third rider in history to win the Vuelta a Espana and Tour de France in the same year on Sunday.

Froome beat four-time Grand Tour winner Vincenzo Nibali by 2:15, with Russia's Ilnur Zakarin completing the podium in the general classification, as

Matteo Trentin claimed his fourth victory of the race on the 21st and final stage.

"I would say this victory is special because it is the first time anyone who has ever won the Tour de France and gone onto win the Vuelta a Espana starting less than one month apart," said Froome.

The Briton joins Frenchmen Jacques Anquetil (1963) and Bernard Hinault (1978) as the only riders to win the Tour and Vuelta in the same year.

But Froome is the first man to win both races since the Vuelta was moved to after the Tour in the racing calendar in 1995.

"That was a huge challenge from an athletic point of view to try and be at the top level for that long was such a big challenge."

Froome, a four-time winner of the Tour de France, had previously finished runner-up at the Vuelta on three occasions in 2011, 2014 and 2016.

The Sky rider led the race all the way from stage three to Madrid thanks to wins on stage nine and the individual time trial on stage 16.

"To have been here for the past six years trying to win the Vuelta and being three times second it is such an amazing feeling to have eventually won this red jersey. It is really emotional and at this moment I couldn't be happier," Froome said.

Trentin continued his domination of the few sprint stages of the three-week race after a 117.6km ride from Arroyomolinos to Madrid, ending in a nine-lap circuit through the centre of the Spanish capital.

However, he was denied the green jersey for the points classification by an insatiable Froome, who sprinted to maintain his lead by finishing 11th on the stage.

"It was a risk sprinting trying to get points for the green jersey," added Froome.

"There is a big risk of crashing in the final, but at the end of the day I'm a bike racer and there is a competition.

"It was probably the only chance in my career to ever win the points classification in a Grand Tour."

Trentin was surprised by Froome's tactics, but proud as the only sprinter to have competed for the jersey in a race filled with demanding mountain climbs.

"He told me he wanted to defend it and he did," said Trentin. With four victories I don't have the jersey, it's kind of a joke. It is a pity but I can survive."

There was also an emotional send-off for Alberto Contador on his final day as a professional cyclist.

The three-time Vuelta winner signed off in style with victory on the steep mountain climb to Alto de l'Angliru on Saturday and was given the honour of leading the peloton around the first lap of the Madrid circuit.

"The whole race has been special," said Contador, who also performed a lap of honour before the adoring Spanish crowds. "Yesterday was as good as it gets. It was a stage I'll always remember andI feel very fortunate."

A winner of seven Grand Tours, Contador is one of just six riders to have won all three of the Tour de France, Giro d'Italia and the Vuelta.