Frenchman Romain Bardet apologised after being kicked out of the Paris-Nice race at the end of Sunday's opening stage for hanging onto a team car.
One of the pre-race favourites, last year's Tour de France runner-up had crashed in the final 25km of a frantic and enthralling stage animated by wind and rain.
But he stooped to illegal means to try to catch the peloton by holding onto his team car.
"We made a mistake through a lack of lucidity at a key moment of the stage, taken hurriedly due to my crash and the circumstances of a fantastic and animated stage. I'm deeply sorry," said a contrite Bardet, 26.
"Nothing justifies the prolonged help of the support cars when fixing (a problem with the bike).
"This practice, too often tacitly tolerated in the peloton, is now faced with safeguards that are necessary to guarantee the integrity of our sport."
While Bardet was apologetic, his AG2R team manager Vincent Lavenu felt the punishment was "very severe" and insisted the rider was blameless.
"I want to clear Romain's name because he doesn't deserve a bad image given we know all about his integrity," he said.
"The punishment doesn't fit at all with his state of mind, his philosophy -- he is someone fundamentally respectful."
Bardet was also fined 200 Swiss francs (186 euros, $198) while AG2R sports director Julien Jurdie was kicked off the race, alongside the offending team car.
Frenchman Arnaud Demare outsprinted compatriot Julian Alaphilippe to win the 148.5km stage of the week-long race, with Norway's Alexander Kristoff third at the finish in the west Parisian suburbs.
Bardet was amongst a group of favourites including Australia's Richie Porte and Alberto Contador of Spain to have been caught out by a split in the peloton caused by strong winds just 40km into the race.
They were forced to chase for more than 100km and eventually came in around a minute behind the winner.
"That was a crazy race! I really enjoyed the splits in the peloton," enthused Demare.
"I didn't think a breakaway would form so soon... but there was the element of surprise. At the finish, everyone was spent."
Ireland's Dan Martin, Frenchman Tony Gallopin and Team Sky's Colombian climber Sergio Henao, all possible overall contenders, lost only nine seconds to Demare and gained significant time on the other title hopefuls.
Porte, the champion in 2013 and 2015, came in 47 seconds down while Contador, winner in 2007 and 2010, lost 1min 04sec.
Demare had also won the opening stage last year, shortly before going on to win the first high-profile 'Monument' one-day classic of the season, Milan-Sanremo.
Monday's second stage of the 'Race to the Sun' covers 195km from Rochefort-en-Yvelines to Amilly.