Primoz Roglic powered ahead of the peloton to win stage four of Paris-Nice on Wednesday and take the overall lead in the eight-day race, while Giro d'Italia winner Tao Geoghegan Hart was forced out after hitting his head in a fall.

Jumbo-Visma rider Roglic skipped clear through the Beaujolais vineyards and leads the 'Race to the Sun' by 35 seconds from last season's champion Max Schachmann, while French rider Guillaume Martin is third at 37sec.

Tao Geoghegan Hart of Ineos fell on a downhill corner with 20km to go and pulled out after struggling to rejoin the peloton.

"Landed on my head today," he tweeted after the stage, thanking Ineos and medical staff "for putting my long-term welfare first when it was clear I wasn't 100%. Little rest, no screen-time & hopefully back soon".

The International Cycling Union issued a new protocol on head injuries last December requiring immediate withdrawal if a rider shows concussion symptoms.

"It was the right decision to stop him. We won't take any risks," Ineos sport director Gabriel Rasch said.

"He landed on his face and head and he felt a bit iffy," Rasch said after Geoghegan Hart slipped, also hurting his knee, on the descent of Mont Brouilly.

The Englishman's withdrawal deprives Ineos of its team leader after Australian Richie Porte retired on Sunday following a crash on the first stage.

Jumbo double 

Roglic paid tribute to his team's performance in the Tirreno-Adriatico first stage in Italy on the same day, also won by Jumbo with Wout van Aert.

"We're super happy with the two wins," Roglic said of his team which has ascended over the past year to become a dominant force in the peloton.

"Obviously I'm more happy about my result, I proved to myself I was in good shape," said the 31-year-old Roglic, who is racing in France for the first time since his Tour de France meltdown on the penultimate day last September.

"It's beautiful and I'm super happy for the team."

The Slovenian produced a trademark devastating surge to grab a three-second time bonus halfway up the final hill. Then, with his rivals struggling after an unrelentingly testing 188km run from Chalon-Sur-Soane to Chiroubles, Roglic kept going to finish 12 seconds ahead of his closest pursuer.

"It was a hard day but I had good legs. Now the aim of course is to still have the lead when we get to Nice," added a relaxed-looking Roglic.

Home Tour de France hope Martin said his podium finish boded well for the rest of the season.

"Roglic was once again imperial, so there was no stopping him. Considering I had a mechanical, I'll take third place on my first summit finish of the season," said the 27-year-old who finished 11th on the 2020 Tour and won the king of the mountains jersey at the Vuelta a Espana.