He could not sustain the sudden change of pace when Alaphilippe broke clear in the short ascent to the Col des Quatre Chemins before being joined by Hirschi, and further up the road by Yates.
“I wanted to try something. It was like a one-day race and it suits my profile,” Alaphilippe said.
“It’s a big emotion because I’ve won on the Tour. I haven’t won (a race) since the start of the season. It’s great to make it. It was tough but I’m super happy to have won.”
The trio opened a 20-second gap but, with the peloton closing in rapidly, Alaphilippe launched his triumphant sprint in front of a handful of fans as Nice is on red alert amid the COVID-19 crisis.
The Deceuninck-Quick Step rider pointed his finger to the sky before collapsing in tears after the line, dedicating his win to his father, who died two months ago.
A darling of French cycling, Alaphilippe’s turn in yellow during the 2019 edition helped turn it into a thriller. Last year, Alaphilippe took the yellow jersey for the first time after the third stage. While he relinquished it on stage 6, it was back in his possession following stage 8 and he unexpectedly held on to it until stage 19, surrendering it only two days before Paris.
“You have to respect the yellow jersey so, of course, I’m going to defend it again,” said Alaphilippe.
Thibaut Pinot (Groupama–FDJ), tipped as the rider most likely to end France’s 35-year wait for a home-grown winner, said he was worried by a back problem after a crash on Saturday, but he had a quiet day in the bunch.
His key lieutenant David Gaudu, suffering from a lower back injury, looked to be on the verge of abandoning the race after being dropped on the flat in the first kilometres, but the Frenchman grinded on and rejoined the peloton before the first climb of the day to the Col Saint Martin.
Another pre-race favourite, Tom Dumoulin (Jumbo–Visma), hit the ground on the last climb after touching the wheel of Michal Kwiatkowski (Ineos), but the Dutchman appeared unhurt.
“It was a bit of a stupid fall,” said Dumoulin. “I don’t know exactly what happened. I looked to the left and, at that moment, Kwiatkowski passed by and before I knew it I was lying on the ground.
“Luckily I didn’t get hurt, just bumped my knee a little. I think it is OK.”
Overnight yellow jersey holder Alexander Kristoff (UAE Team Emirates) lost touch with the peloton five kilometres from the top of the Col de Turini way before the action started.