With 3.5km to go, the Brit used the final uncategorised bump of the stage to surge from the peloton and pass the last rider left from the day's break, Mathias Frank (IAM). Luis Leon Sanchez (Astana) and Fabio Felline (Trek Factory) rounded out the podium for the 163km stage from Monforte de Lemos to Ribera Sacra.
"Pretty crazy! There were lots of twists and turns in the finale. I timed my attack to perfection, the day worked out very well for us in the end," Yates said.
”I'm really happy. We wanted to go in there and try to make a hard race. The team did some great work in the beginning and set things up really well for me."
But it wasn't OBE's plan for Yates to attack, according to director Neil Stephens.
"It wasn’t really the plan but the decision was made by the guys on the road and as the situation progressed we wanted to try and nullify the threat of the other teams and it ended up being a fantastic effort and win from Simon," he said.
”We’d done a detailed reconnaissance of the stage beforehand and we knew it was going to be difficult, but you can never be sure what the other teams are going to do. So we decided to go on the front foot and liven things up.”
— ORICA-BikeExchange (@ORICA_BE) August 25, 2016
As it happened
Several attacks from the gun were thwarted by a determined peloton, the break of the day only succeeding after 45 kilometres raced.
The break comprised Andrey Zeits (Astana), Kevin Reza (FDJ), Jan Bakelants (AG2R - La Mondiale), Alberto Losada (Katusha), Gert Dockx (Lotto Soudal), Omar Fraile (Dimension Data), Mathias Frank (IAM Cycling), Valerio Conti (Lampre - Merida), Laurent Didier (Trek-Segafredo) José Mendes and Gregor Muhlberger (Bora-Argon18).
But with Mendes just two minutes and 51 seconds behind race leader Darwin Atapuma, BMC and Sky did not allow the leaders' advantage to exceed two minutes and 40 seconds in the lead up to the only categorised climb of the day, Alto Alenza.
OBE took charge of the bunch once the leaders were within five kilometres of the Alto Alenza and 55 kilometres from the finish. Their work paid off with the lead dropping to one minute and 24 seconds once the leaders hit the lower slopes of the category two 10.9km 5.1 per cent climb.
2015 Vuelta King of the Mountain winner Fraile attacked his fellow escapees and by the top of the Alenza built a three minute advantage over the peloton and one minute over his first group of chasers Zeits, Baeklants, Losada, Didier and Frank.
— Vuelta a España (@lavuelta) August 25, 2016
Movistar took charge on the descent capitalising on Tinkoff's hard work up the climb and reducing the deficit to Fraile to one minute and 48 seconds.
Various riders were in no man's land in between but Zeits, Bakelants and Frank persisted, swallowing up Fraile 19 kilometres from the finish. Frank attacked immediately with five kilometres remaining. The Swiss had 30 seconds on the looming peloton which now contained Zeits and Bakelants.
Dani Moreno (Movistar) jumped from the peloton with Yates and Ben Hermans closely behind, Yates timing his attack to catch and pass Frank.
In other news
Injuries sustained in a crash on stage 3 became too much for Miguel Angel Lopez (Astana), the GC contender abandoning during today's stage after another fall.
"Miguel Angel Lopez’s abandon is a bad shot for the whole team but is part of the risks of this work," Astana direct Dmitri Sedoun said.