Australian Ben O'Connor has desperately hung on to the red leaders jersey at the Vuelta a España by just 5 seconds on a brutal day in the Asturias mountains of northern Spain.

Decathlon–AG2R La Mondiale described O'Connor's ride as "heroic" and that he "fought like a lion" to retain his jersey, as three-time winner Primoz Roglič took another big bite out of the Australian's lead.

There was some confusion at the finish where O'Connor, under the impression that the podium presentation would take place at the base of the Lagos de Covadonga climb, descended the 15-kilometre slope.

After being alerted to the actual location of the presentation, O'Connor was forced into a car and back up the slope, with a police escort dispatched to ease his progress.

"I'm not happy, I can tell you that," O'Connor laughed after the initial frustration had worn off.

"I'm trying to put on a brave face, but internally I'm a bit pissed.

"I was told to descend down to the bottom, and I descended all the way down to the bottom, but then I was told to come back up. That was a bit frustrating to be honest.

"I could definitely do with a hot shower now, I'm absolutely freezing."

The Australian was fined 1,000 Swiss Francs, ($1,750) for failing to attend the official ceremony within 10 minutes of the stage finish, and was also penalised 20 UCI points.

O'Connor paid credit to his teammate Valentin Paret-Peintre for his efforts in keeping him in red for at least another day.

"I was pretty worn at the finish," O'Connor said. 

"Valentin was really, really strong today, I'm grateful for him to be back like he was on the Giro. Everyone on our team is super proud, it's been an experience that we really haven't had before. 

"To have 11 days in the red jersey already so far has been a pretty sweet experience for us all.

The stage was less fortuitous for another of the jersey wearers though, with three-time stage winner Wout van Aert forced to abandon the race after crashing on a descent.

Marc Soler broke clear on the steep final climb to win the 181km stage from Luanco to the storied Lagos de Covadonga summit by 18 seconds from Filippo Zana. Max Poole was third, trailing 23 seconds behind Soler.

Four minutes behind Soler, Roglič crossed the line with Enric Mas — third overall and now 1 minute, 15 seconds back — as O'Connor trailed trying to limit the damage.

Light drizzle, known locally as Orbayu, made the roads on stage 16 desperately treacherous.

Wearing the green jersey as leader of the points classification, Van Aert also led the mountains standings when he was among three riders that crashed on a descent of Collada Llomena, about 50km from the finish.

That puts Australian Kaden Groves, winner of two stages so far, in the green points leaders jersey, and fellow Aussie Jay Vine in command of the polka dots mountains classification, meaning Australians will wear all three major jerseys.

"Absolutely not the way I wanted to take the polka dots," Vine said of taking the jersey after Van Aert's withdrawal.

"Honestly, he was beating me in the sprints at the top of these climbs anyway … the mountains jersey is a bonus."

Groves, for his part, said it was "a pretty terrible way to wear the green".

Roglič started the stage 1 minute, 3 seconds behind O'Connor, whose margin over the Slovenian star had been close to 5 minutes after winning the sixth stage.

A breakaway of 17 riders including Van Aert had led the peloton by as much as 9 minutes and the Belgian star spent time out in front after going clear on a descent.

Van Aert tried to continue with cuts and injuries on his right knee but abandoned the race minutes later. He won three of the first 10 stages of the Vuelta.

Stage 17 on Wednesday is a 141.5km ride from Arnuero with a relatively flat finish into Santander.

ABC/wires