Fabio Aru achieves the impossible to take Vuelta a España to the wire

The smiles at the Astana team bus were as wide as if they had won the stage today in the Vuelta a España.

Team leader Fabio Aru warmed down on his bike, grinning between sips from his water bottle, after he rode the time trial of his life at Burgos to keep this pulsating Grand Tour in the balance.

Around him, the team said again and again, "Tre secondi [three seconds]". Aru had achieved what most thought had thought was impossible — he had stayed within touching distance of time trial specialist Tom Dumoulin (Giant-Alpecin), and this race was still very much alive with only four stages to go.

As predicted, Dumoulin won the stage and overtook both Aru and this morning's leader, Joaquím Rodríguez (Katusha). Surprisingly, however, his lead over Aru stands at just three seconds.

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Aru finished 10th on the 38.7-kilometre stage at 1-53 minutes, enough to keep dreaming of the Vuelta overall title when the three-week tour ends in Madrid on Sunday.

"I'm happy with the ride. I can't be completely happy because I'm never happy when I'm not in the lead, but it's not bad," Aru said.

He looked down at his bike to his right and briefly ahead when answering. When he did, his grin was visible.

"When I finished and I saw was in second, I felt it was a good time trial. At three seconds is not bad at all."

Aru won some of the biggest amateur stage races before turning professional, including the Giro della Valle d'Aosta twice. As a pro, he progressed to place third in the Giro d'Italia last year and second this May to Alberto Contador.

His time trial abilities were always lacking, however. So much so, the team sent him to California this winter to work on his time trailing in a wind tunnel with bike sponsor Specialized.

"I worked a lot on my time trialling," he added. "What I did at the Giro [3-01 behind winner Vasil Kiryienka (Sky)] is not a good comparison because I was feeling bad in the days beforehand.

"At the Tour of Poland, I rode a good time trial. I'm not a time trial rider, but I need to be able to save myself in them. I've been working on it."

Aru comes across as shy even in good moments. He tried to end the conversation early twice, succeeding on the second time and escaping to the safety of Astana's turquoise bus.

The two big days ahead, tomorrow and Saturday, both include climbs to 1750-1800 metres before a descent to the finish. In theory, to win the Vuelta, Aru only needs to drop less gifted climber Dumoulin and hold any advantage on the descent to the finish line.

"That makes it sound so easy," he said getting off his bike and heading to the door of the bus — but today's performance proves Aru's determination to win a race that is now too close to call.