The Dutchman surged around the final corner into the line and jumped from the wheel of Stage 2 winner Mads Pedersen (Trek-Segafredo) to secure his first stage of the season. Tim Merlier (Soudal-QuickStep) was next fastest to finish third on the day.
After finishing a narrow second to Pedersen on Stage 2, Kooij was happy to have kept the faith and made a comeback to take a win of his own in the race.
“It’s nice. I won a few races last year, but this is definitely the nicest so far,” Kooij said after the finish.
“I was a bit far back under the flamme rouge, and I took the left side of the roundabout, which was a good choice. I was in a good position. Edoardo Affini flew by, and I was on the Pedersen’s wheel, and this time I was able to get out of his wheel.
“Coming close and finishing second is not bad, but the victories are the ones that count, so I’m really happy to take the win today."
Tadej Pogačar (UAE Team Emirates) became the first rider in the race to retain his overall lead for the second day in the row, finishing safely within the peloton as second-placed David Gaudu (Groupama-FDJ) picked up bonus seconds to sit 6 seconds behind. Jonas Vingegaard (Jumbo-Visma) is third, now 46 seconds back from his Slovenian rival.
“I enjoyed the first day in yellow, and it was a nice day, finally some sun and no stress, so it was a nice day,” Pogačar said after the stage, with three stages left now for him to secure the race win.
“I know the last stage well, it’s my home training roads and it’s a nice stage, but I don’t know the roads tomorrow or the day after, and the route was published too late to do the recons.
“Even tomorrow, it will be stressful, a classic stage, and anything can happen with a lot of surprises. Stage 7 is the most predictable, and you need to measure your effort to the top. I like the final stage the most.”
Paris-Nice continues tonight with Stage 6, an undulating course with five climbs on the 197.5 kilometre route from Tourves to the finish in La Colle-sur-Loup. Watch the action live from 12:55am (AEDT) on SBS and SBS On Demand.