Fabio Aru in red after Astana break Tom Dumoulin, Ruben Plaza wins stage 20

Overnight race leader Dumoulin (Giant-Alpecin) was distanced by Italian Aru on the third of four Cat.1 climbs in the penultimate stage of the race, a mountainous 186km ride from San Lorenzo de El Escorial to Cercedilla.

Aided by three Astana team-mates, Aru put a huge wedge between himself and Dumoulin on the final climb as the Dutchman lost his grip on the red jersey and plummeted off the podium and out of the top five.

By the time Aru crossed the finish line after a fast descent off the back of the Puerto de Cotos climb the Sicilian could afford to sit up and celebrate in style, punching the air before hugging Astana team-mates Luis Leon Sachez and Mikel Landa, who had helped pace him to a first Grand Tour victory.

“This victory is thanks to my team-mates – it’s not just about me,” said Aru, runner-up in the Giro d’Italia in May.

“They’ve been phenomenal for the whole Vuelta – Mikel, Luis Leon and Dario Cataldo – and we think of the guys who aren’t here, Paolo Tiralongo and Vincenzo Nibali. We had our difficulties at the start of this Giro but we’ve worked hard and we’ve been very united.”

Aru finished in a group that included Spanish veteran Joaquim Rodriguez, who rose to second place in the general classification, 1:17 behind Aru.

Poland’s Rafal Majka (Tinkoff-Saxo) attacked with Colombian Nairo Quintana (Movistar) on the final climb to pile pressure on Rodriguez in the battle for second place – although Majka eventually came up 12 seconds too short and had to settle for the third and final spot on the podium.

The final top five ahead of Sunday’s processional stage into Madrid was completed by Quintana and compatriot Esteban Chaves, the winner of two stages in the opening week of the race for Orica-GreenEdge.

Despite enjoying three separate stints in the red jersey, Dumoulin was pushed down to sixth place after coming home in a group almost four minutes down on Aru, whom he led by a slender six seconds going into the decider.

“At the moment it’s just disappointment. Tomorrow I’ll be proud but today it’s just disappointment,” a dejected Dumoulin told reporters after his day from hell.

“I was just empty, I had no legs. I fought for what it was worth but I had an idea [that it was all over] and in the end you just have to deal with it.”

A captivating stage was won by Spanish veteran Plaza of Lampre-Merida, who attacked from a large breakaway of 39 riders from more than 100km out to take his second Grand Tour stage win of the season.

Portugal’s Jose Goncalves (Caja Rural) pipped Italian stage 14 winner Alessandro De Marchi (BMC) for second place when the chasing duo came home just over a minute behind Plaza.

Majka and Quintana caught the remnants of the large break with the Pole crossing the line 2:42 down in 12th place – two seconds ahead of Quintana.

Aru crossed the line with his arms around team-mate Sanchez just under a minute later – and there was no need to set the stopwatch running.

The six seconds that seemed like a mountain to climb hours earlier ended up being completely immaterial when a disconsolate Dumoulin rolled in 7:30 down on Plaza, whose superb win will be ever overshadowed by the Astana masterclass that delivered a first major stage race victory to 25-year-old Aru.

To win any race from a solo break is quite an achievement but to win the penultimate stage of the Vuelta off the back of a competitive Tour de France – and to do so after riding alone for 114km – was a sight to behold.

Plaza, winner of stage 16 of the Tour in Gap, was in a leading group of 11 riders when he surged ahead on the second of four Cat.1 climbs, the Puerto de la Morcuera. Behind him a chase group of 38 riders formed when a second break finally bridged the gap on that initial leading group.

Plaza held a gap of 2:30 going over the summit, with the peloton – at the point still being controlled by Dumoulin’s Giant-Alpecin team – riding more than 11 minutes in arrears.

Although Plaza’s gap dropped to just one minute ahead of the second, reverse ascent of the Puerto de la Morcuera, the 35-year-old extended his lead on the climb before holding his nerve on the final ascent.

What a ride – and what a win for the Spanish veteran: 10 years after his last and only previous win on the Vuelta.

Reducing Plaza’s stellar ride very much to a subplot, the battle for the red jersey intensified on the second ascent of the Morcuera when Aru came to the front of a reduced main pack with Landa.

With Sanchez and Andre Zeits riding further up the road in the break, Astana had all their pieces in place ahead of the perfect move for checkmate.

Aru and Landa cranked out a hefty tempo with Quintana and Majka in tow to open up a small gap over Dumoulin with 50km remaining. With the help of Rodriguez and Chaves, Dumoulin managed to bridge over before Aru and Landa turned the screw once again.

Dumoulin trailed his rival by 20 seconds going over the summit alongside Team Sky’s Mikel Nieve. The duo had managed to reduce the gap to 10 seconds on the descent before it began to balloon after both Sanchez and Zeits had sat up from the break to join team-mates Aru and Landa.

With Dumoulin dropping further back on the final climb of the Puerto de Cotos, Quintana and Majka sniffed an opportunity to move onto the podium.

It was Quintana who made the initial attack, bounding clear of Aru et al inside the final 20km. Majka followed and the pair crested the summit with a 35 second gap over Aru and well over three minutes on Dumoulin.

Quintana needed to drop Majka or rely on Rodriguez becoming unstuck back in the Aru group; in the end neither happened. The remainder of the descent had an air of finality about it – with aerial pictures showing Astana riders starting to celebrate well before their man Aru had crossed the line.

They may have left it to the last possible chance – but didn’t they do well.

COMING UP: Giant-Alpecin can draw a line under their Dumoulin disappointment by teeing up John Degenkolb for a sprint win on the streets of Madrid after the 98km city criterium-style stage 21.