The Astana rider claimed his first career win at the Tour after staying ahead of Ion Izagirre and Bauke Mollema in a sprint over the final 200 meters of the hilly 181.5-kilometer (112.7-mile) leg from Millau that finished in a long descent to Carcassonne.
The three riders were the last of a breakaway group of 29 cyclists.
The peloton crossed the line some 13 minutes later, with Team Sky’s Geraint Thomas and Chris Froome present along with Team Sunweb’s Tom Dumoulin to ensure there was no change at the top of the general classification ahead of Monday’s rest day.
Thomas continues to lead Froome by one minute and 39 seconds, with Dumoulin a further 11 seconds back.
World champion Peter Sagan was one of 29 riders to get into the day’s break, and he took third place in the day’s intermediate sprint to ensure he now simply needs to reach Paris to win the points classification for a sixth time – mathematically unable to be caught with a full week of the Tour to spare.
The race will have a rest day on Monday. That pause precedes the four days in the Pyrenees, followed by the individual time trial on the penultimate day of the race.
The racing returns on Tuesday with Stage 16, a 218-kilometer mountain trek from Carcassonne to Bagneres-de-Luchon.