Joaquim Rodriguez wins stage 15 to close the gap on Fabio Aru

Katusha climber Rodriguez, 36, made his decisive attack inside the final kilometre of the 176km stage from the seaside town of Comillas to the mountain village of Sotres in Cabrales.

Rodriguez dropped Italian rival Aru (Astana) before riding clear to win the stage by 12 seconds over Poland's Rafal Majka (Tinkoff-Saxo), with Aru coming home three seconds further back for fifth.

Collecting 10 bonus seconds for his success, Rodriguez moved to within one second of Aru's overall lead ahead of the third of three back-to-back summit finishes on Monday.

Majka himself moved up into third place on GC at the expense of Dutchman Tom Dumoulin (Giant-Alpecin), who limited his losses to 51 seconds to drop to fourth place 1:25 in arrears – and one second behind the impressive Polish climber.

An excellent day for Katusha was capped by third place for Rodriguez’s team-mate Dani Moreno, who finished the 12.7km long Alto de Sotres strongly alongside fourth-place Nairo Quintana (Movistar) and Aru.

Quintana, twice runner-up on the Tour de France, showed his rivals that he had shrugged off a week of illness by attacking with 10km remaining of the final climb.

The Colombian’s attack came to nothing after the Astana team-mates of Aru combined to reel him in while lone escapee Haimar Zubeldia (Trek Factory Racing) continued plodding away further up the road with a minute’s advantage.

It was not until Zubeldia was caught with 2km remaining that Quintana upped the tempo again – but the pint-sized Colombian was unable to match the accelerations of Rodriguez.

“I’m very happy to have this win,” said Rodriguez, whose ninth Vuelta stage victory saw him move to the top of the green jersey points classification. “I feel very good. For me this is one of the best Vueltas I have done. I’m calm and I’m riding within my limits.”

Sardinian Aru, runner-up in May’s Giro d’Italia behind Spaniard Alberto Contador, was upbeat despite seeing his overall lead slashed by Rodriguez.

“Today Movistar set the pace at the beginning and ‘Purito’ did great things at the end so I congratulate him for his victory,” 25-year-old Aru said.

“But I’m still in red and we have another mountain stage ahead of the time trial, which will be very difficult for many riders.”

Basque veteran Zubeldia was the most experienced of a large group which only formed 35km into the stage after another fast start on the coast in northern Spain.

Tour de France stage winners Pierre Rolland (Europcar) and Blel Kadri (Ag2R-La Mondiale) starred in a break that also included Ricardo Vilela (Caja Rural-Seguros RGA), Dominique Rollin (Cofidis), Brayan Ramirez (Colombia), Nikolas Maes (Etixx-QuickStep), Natnael Berhane (MTN-Qhubeka) and Maarten Tjallingii (LottoNL-Jumbo).

After negotiating the irregular Cat.2 Alto del Torno with 60km remaining, the leaders built up a maximum advantage of five minutes over the peloton, which was being led for the most part by the Movistar team of Quintana.

The gap had been whittled down to just over a minute when the break hit the start of the final climb. Both Frenchman Kadri and Eritrean Berhane put in individual digs before Zubeldia rode clear of his fellow escapees with less than 11km remaining.

A veteran of 25 Grand Tours prior to this, his 14th Vuelta, Zubeldia rode ahead in search of an elusive major stage race victory while the GC fireworks were being lit further back down the road.

Trailing Aru by three minutes on GC, Quintana had made no secret of his intention to attack on the final climb, telling reporters as much prior to the stage.

The 25-year-old kept his word, attacking from a whittled down pack with 10km remaining in what appeared to be an all-or-nothing type of manoeuvre.

Astana sent Luis Leon Sanchez up the road to mark the attack and Quintana soon found himself back with the other race favourites as both Astana and Movistar sent riders to the front to set a fast tempo.

Time trial specialist Dumoulin was eventually shelled out the back of the pack while Quintana was ultimately unable to match the pace of Rodriguez when the veteran Spaniard made his move.

Aru and Majka followed the Katusha pace-setter before Aru dropped back – eventually to be pipped by Quintana for fourth place. With just one second separating first and second on GC, the scene is set perfectly for Monday’s decisive day in the Asturias.

COMING UP: Seven categorised climbs feature in the 185km stage from Luarca to Quiros including the rasping final HC climb of the Alto Ermita de Alba.