Marc Soler of UAE-Team Emirates won the 16th stage of the Vuelta a Espana on Sunday, while Ben O'Connor of Decathlon AG2R- La Mondiale once again defended his overall lead against the attacks of Primoz Roglic of Red Bull-Bora Hansgrohe and Enric Mas of Movistar at the end of the grueling climb to the Lagos de Covadonga.

O'Connor looked as if he was destined to finally surrender his lead as he slipped behind Mas, Roglic and Mikel Landa of T Rex-Quick Step around five kilometers from the finish of another tough mountain stage.

However, once again, the Australian rider showed his grit and courage to dig deep and claw back enough time in the closing stages to cling on to the leader's red jersey by just five seconds.

It was clear early that the day would be divided into two separate races, one for the stage win and the other for the overall race lead.

The stage began with a breakaway of 17 riders, including Wout van Aert, who was searching for points to try and climb the mountain's jersey.

The escape opened a lead of 10 minutes before the peloton began to up the pace on the first category Collada Llomena climb.

Van Aert crossed the summit in first place but crashed on a slippery descent and was forced out of the race with a nasty-looking knee injury.

The duel for the stage came down to a duel between Soler, 21-year-old Max Poole of Team DSM-firmenich PostNL and Filippo Zana of Jayco-AlUla, with Soler claiming the win his continued efforts in breakaways in this Vuelta have deserved.

The race for the overall lead dynamited on the final climb when Landa launched the first of a series of attacks with O'Connor starting to cede at around five kilometers as Roglic and Enric Mas of Movistar moved ahead.

Mas tried to break Roglic, but although he had a more explosive kick on the steep gradients, Roglic kept calm and slowly reeled him back, with the pair again finishing together, as O'Connor battled home 58 seconds behind.

Wednesday should give the riders some respite with a 141-kilometer stage that contains two second category climbs, but which should see a bunch sprint in Santander unless a breakaway is able to get all the way to the line.