It was a powerhouse performance from the Slovakian superstar, making the most of a moment of hesitation with 54 kilometres remaining in the race. He surged clear from the other favourites and picked up the remnants of the breakaway before taking the victory in a sprint inside the Roubaix velodrome.
"I'm so tired after this race," said Sagan, "but I have to say this year, I was never involved in a crash, no wasted energy. There was one step forward with the attack and I kept going through to the finish.
"I stayed much better than in all other years I finished, I was much more tired then than today. I have to say thanks to teammates, they did a great job today. It's an amazing feeling."
The race began with an unsettled peloton with multiple teams very keen to make sure they were part of the early move.
There were 40km of racing before the breakaway finally got itself established with Sven Erik Bystrøm (UAE Team Emirates), Marc Soler (Movistar Team), Ludovic Robeet (WB Aqua Protect Veranclassic), Jimmy Duquennoy (WB Aqua Protect Veranclassic), Jelle Wallays (Lotto Soudal), Geoffrey Soupe (Cofidis Solutions Credits), Gatis Smukulis (Delko Marseille Provence), Jay Robert Thomson (Dimension Data) and eventual second-placed finisher Dillier all making the move.
The group of nine pushed out their advantage to a maximum lead of eight minutes and 30 seconds before the peloton ramped up the pace heading into the early cobbled sectors.
Mike Teunissen (Sunweb) and Phillipe Gilbert (Quick-Step Floors) used the final metres of the Forest of Arenberg to accelerate off the front of the peloton. They picked up a number of dropped riders from the early escape but the peloton proved attentive to the danger and kept the move well in check.
Zdenek Stybar (Quick-Step Floors) attacked with over 70km remaining in the race, the first of the contenders to make a move, dangling off the front before he was eventually brought back into the fold. The initial break was still clear of the main bunch, but only with a buffer of just under a minute.
A few Greg van Avermaet (BMC) surges began to break up the main bunch, but it was Sagan who managed to jump clear. Using the indecision of others in the group, the reigning world champion accelerated away with little reaction from the riders behind with over 50km to race.
Sagan quickly made his way over to the remnants of the early break in Bystrøm, Wallays and Dillier, beginning a long effort to keep his advantage over the chasing pack. Bystrom was almost immediately dropped, but the other two riders continued to pull turns with the world champion.
The gap pushed out initially as attacks and lack of cooperation saw the chase stymied and the gap stretched out to a minute with 35km remaining.
Niki Terpstra (Quick-Step Floors), Van Avermaet, Sep Vanmarcke, Taylor Phinney (both EF Education First-Drapac), Jens Debusschere (Lotto Soudal), Wout Van Aert (Verandas Willems) and Jasper Stuyven (Trek-Segafredo) formed the pursuing group but despite the calibre of riders present, couldn't make much of an impact on the gap to the front.
Wallays was the first of the front trio to falter, slipping off Sagan's wheel with 25km remaining. Dillier proved stronger, still swapping off turns with the world champion over the final sectors and on the run into the finish.
Over the Carrefour d l'Abre, the infamously tough final big section of cobbles, the chasing group was reduced to an elite group of four as van Avermaet, Terpstra, Vanmarcke and Stuyven began to cooperate in a last ditch effort to reel the front two back.
Their efforts proved fruitless and it was clear that the race would be decided by Sagan and the visibly flagging Swiss champion Dillier, who had been off the front of the race for 220km.
The traditional velodrome finish saw a cagey wait for sprint with Dillier leading out, but it was Sagan who caught out the AG2R-La Mondiale rider, launching down the incline and holding on for the victory.
Niki Terpstra continued his recent superb form by attacking late to go clear of the chasing group to grab the final spot on the podium.
Silvan Dillier (L), Peter Sagan (C) and Niki Terpstra (R) enjoy the moment. (Getty) Source: Getty
