The Frenchman completed the race in 5:01:49, beating Astana Pro’s Miguel Ángel López by 28 seconds. Red-jersey-wearer Simon Yates of Mitchelton-Scott completed the podium a further two seconds back.
Yates extended his race lead to 26 seconds over Movistar’s Alejandro Valverde, with a total general classification time of 64:13:33.
After the first 40km of the race a 12-man breakaway group had formed and created a gap of 3:08 over the peloton.
George Bennett was the highest-placed among the GC contenders in the group, ranked 21st and 10:03 behind Yates.
Several kilometres later, the gap increased to just under four minutes.
With 103km left Mitchelton-Scott were setting a steady and aggressive pace in the peloton, but still the gap widened to 4:40 and then to five minutes with 100km to go.
Mitchelton-Scott were joined by Astana Pro with 82km left as they attempted to reel in the escapees. Astana Pro managed to pin five riders to the front of the peloton several kilometres later.
On a steep climb with 65km left the lead was whittled down to 3:20. Astana Pro remained in control at the head of the peloton, but the gap increased to four minutes as the breakaway group hit the coastline.
Dimension Data’s Ben King sprinted to the top of the second climb of the Mirador del Fito to secure first place in the break with about 40km remaining.
However, with 30km left the break disintegrated due to the steep ascents.
Iván García Cortina, from within the break, took the lead as the group headed towards the Lagos de Covadonga.
The Spaniard managed to create a 45-second gap with 14km left. The gap to the peloton narrowed to 2:45 before the final decisive climb, the Lagos de Covadonga. This is 11.7km long with a 7.2 per cent gradient.
Red-jersey-holder Yates was at the back of the 80-man peloton at the time as Cortina extended his lead to 1:50 with 10km left.
However, the break began to be reeled in by the peloton. Astana Pro continued to maintain an aggressive tempo as all the escapees eventually got caught, with just Cortina solo-leading.
However, Cortina was caught with 8km left. Yates had moved closer to the front of the group as his brother, Adam, stayed near the back to follow any potential attack.
López took a narrow lead with 7km left, before Nairo Quintana bridged the gap. Shortly thereafter Pinot attacked and created distance from the group.
Simon Yates then joined the chase in pursuit of Pinot, with the Frenchman leading by just 10 seconds with 5km to go.
With 3km left Pinot led by 16 seconds, as López, Quintana, Yates and Enric Mas gave chase.
López then created a gap in the closing kilometres. Frustration became evident in the chase, with Yates directing his anger towards Quintana for not attempting to chase down the Colombian.
At the head of affairs Pinot did enough to take the stage spoils, as Yates reinforced his race lead with his podium finish.
It was Pinot’s 23rd career win and third Grand Tour stage win.