Olav Kooij won the opening stage of Paris-Nice by a hair's breadth from Mads Pedersen on Sunday when the 158km hilly run came down to a mass sprint.

The 22-year-old is shaping up as one of the top sprinters in the peloton after his third win of the season and also took the overall lead of the eight-day race from the Paris region to the Riviera town of Nice.

Belgium's Remco Evenepoel, who is using the race as a warm-up for his tilt at the Tour de France this summer, gamely attacked the final hill to take four bonus seconds.

"Remco attacked after the climb so it was a nervous finish, but the guys protected me and lined me up," said Kooij of the Visma team.

"Tomorrow's another sprint stage so I'll try and keep the yellow jersey, as long as possible in fact."

Many of the pure sprinters failed to keep up the pace on the final climb at Les Mureaux, to the south of Paris.

Dylan Groenewegen was over 3min down and Fabio Jakobsen almost 7min behind.

Evenepoel's key rival, Slovenia veteran Primoz Roglic, on his first major outing since quitting Visma for Bora, had a modest ride hiding mainly in the wheels.

A late entry on the roster, Ineos' former Tour and Giro winner Egan Bernal was in the mix on both the climb, where he won bonus seconds, and the sprint as his comeback from life-threatening injuries continues.

Bernal, sixth overall, was looking long term.

"We wanted to make this stage hard for the others, and we did it," said Bernal of the first of eight stages.

"With the bonus seconds it wasn't the main objective, but when I saw the opportunity I went for it and it worked," said South America's only Tour de France winner Bernal.

"It was nervous, really hard, and we did a good job," said the now 27-year-old, who won the Tour de France in 2019.

Monday's second stage is a flat 177.6km run from Thoiry to Montargis, with another mass bunch sprint likely if there is no wind on the vast agricultural plains south of Paris.

The third stage is a team time trial over 30km on Tuesday with Roglic and Evenepoel likely to shine as riders are timed individually.

Stage 1 results

1. Olav Kooij (NED/VIS) 3hr 36min 28sec, 2. Mads Pedersen (DEN/LTK) same time, 3. Laurence Pithie (NZL/GFC) s.t., 4. Nils Eekhoff (NED/DSM) s.t., 5. Madis Mihkels (EST/ICW) s.t., 6. Michael Matthews (AUS/JAY) s.t., 7. Matteo Trentin (ITA/TUD) s.t., 8. Mattias Skjelmose (DEN/LTK) s.t., 9. Sandy Dujardin (FRA/TEN) s.t., 10. Kaden Groves (AUS/ADC)

Overall standings

1. Olav Kooij (NED/VIS) 3hr 36min 18sec, 2. Mads Pedersen (DEN/LTK) at 4sec, 3. Matteo Jorgenson (USA/TJV) s.t., 4. Laurence Pithie (NZL/GFC) at 6sec, 5. Remco Evenepoel (BEL/SOQ) s.t., 6. Egan Bernal (COL/IGD) 8sec, 7. Nils Eekhoff (NED/DSM) 10 sec, 8. Madis Mihkels (EST/ICW) s.t., 9. Michael Matthews (AUS/JAY) s.t., 10. Matteo Trentin (ITA/TUD) s.t.