Australian Richie Porte's hopes of a third Paris-Nice title appear dead and buried after falling more than 15 minutes behind the yellow jersey during stage three.
Ireland's Sam Bennett overpowered a world-class field of sprinters to claim honours on Tuesday.
The Bora-Hansgroghe rider surged at the right time to upstage Norway's Alexander Kristoff and German riders John Degenkolb and Marcel Kittel.
Australia's former Under 23 Road race World Champion Michael Matthews finished fifth on the mainly flat 190-kilometre stage from Chablis to Chalon-sur-Saone, across eastern Burgundy.
France's Arnaud Demare had to settle for sixth but retained his overall lead before Wednesday's decisive time trial in Mont Brouilly.
"I was full of confidence, I had a good feeling in my legs and I was looking for an opportunity. With the support of the team, I was able to do it," Bennett, 26, said after the most significant victory of his career.
"To be honest, I fought for my position to be in the front and I didn't really notice what the other sprinters were doing."
Demare, who won the opening stage, remains six seconds ahead of fellow countryman Julian Alaphilippe overall.
Kristoff, 13 seconds behind, took the third spot ahead of Belgium's Philippe Gilbert, 17 seconds behind.."
Two-time champion Alberto Contador from Spain is still 1:18 behind Demare in the overall standings, while Porte looks unlikely to win a third title, after slipping more than 15 minutes behind the Frenchman.
The race ends on Sunday in the southern city of Nice.
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