The Slovak won a two-up sprint in the Roubaix velodrome against Silvan Dillier (Ag2r La Mondiale) to secure arguably the biggest win of his glittering career.
World champion Sagan adds the Paris-Roubaix win to his 2018 victory in Ghent-Wevelgem, stage win in the Tour Down Under and sixth places in both the Tour of Flanders and Milan-San Remo to amass 1626 WorldTour points.
Dutchman Niki Terpstra (Quick-Step Floors) moves up to second spot with 1297 points behind Sagan after his third place in Roubaix is added to the points he has collected from winning the Tour of Flanders and E3 Harelbeke.
Greg Van Avermaet (BMC Racing) and Jasper Stuyven (Trek-Segafredo) move up to fifth and sixth in the ranking after their Paris-Roubaix rides.
British rider Simon Yates (Mitchelton-Scott) drops out of the top 10, slipping to 12th spot with 760 points.
Quick-Step Floors retain their dominant position at the top of the UCI WorldTour team ranking, well ahead of second-placed Bora-Hansgrohe.
Quick-Step has three riders in the top 10 of the individual ranking: Terpstra, Philippe Gilbert and Elia Viviani.
The next events in the men’s WorldTour calendar are the Ardennes Classics: the Amstel Gold Race on April 15 followed two days later by Flèche Wallonne on April 18, and then Liège-Bastogne-Liège on April 22.
WorldTour points are awarded to riders to place highly in counting events. More prestigious events – such as Paris-Roubaix or the Tour de France – carry more points.
UCI WorldTour men’s ranking (as of April 8)
1. Peter Sagan (Svk) Bora-Hansgrohe, 1626 pts
2. Niki Terpstra (Ned) Quick-Step Floors, 1297 pts
3. Alejandro Valverde (Esp) Movistar, 1079 pts
4. Tiesj Benoot (Bel) Lotto-Soudal, 986 pts
5. Greg Van Avermaet (Bel) BMC Racing, 954 pts
6. Jasper Stuyven (Bel) Trek-Segafredo, 935 pts
7. Daryl Impey (RSA) Mitchelton-Scott, 862 pts
8. Philippe Gilbert (Bel) Quick-Step Floors, 855 pts
9. Arnaud Démare (Fra) Groupama-FDJ, 827 pts
10. Elia Viviani (Ita) Quick-Step Floors, 817 pts
1. Quick-Step Floors, 5366 pts
2. Bora-Hansgrohe, 3426 pts
3. Movistar, 3272 pts
2. Mitchelton-Scott, 3226 pts
3. BMC Racing, 3146 pts