Julian Alaphilippe became the first Frenchman to win a stage in this year's Tour, claiming the 10th stage that included three first-category climbs and a beyond-category climb but ended with a descent and the contenders together in the peloton.
In tears, the 33-year-old - who started the day tenth overall - was taken to the side of the road and forced to quit the race on the ninth stage, just as he had done last year. The single-day race was run on a route that included most of the men's 10th Stage.
"When the big move went, I chose to give it a go and see how Team Sky reacted and they didn't".
One of the overall favorites, Ireland's Dan Martin who won the sixth stage on Thursday, crashed with 17 kms left and lost one minute 16 seconds.
Van Avermaet may have a comfortable cushion, but the BMC Racing rider is predicting his time in the maillot jaune is coming to an end - for this year at least.
"I don't know how many kilometers I was alone - phew, it was a bit risky but I tried to up the pace and I really profited".
Van Avermaet then agreed with a quip from the press pack that he might not get Carte Blanche but maybe he'd a Carte Jaune (yellow), the colour of his jersey. That doesn't mean the team has not had cause to celebrate during this Tour, however.
Three-time champion Peter Sagan came third to hold on to his green jersey. Without Richie, we'll keep fighting in this Tour.
Unfortunately for Van Avermaet, his days in yellow may finally be numbered.
That challenge will be followed by a rest day on Monday before the race shifts to its first mountain stages in the Alps.
By this time Wednesday and nearly certainly by Thursday, the yellow jersey should be in the hands of a rider in the mix to hold it all the way to Paris.
While he seized the moment to attack the main protagonists in the mountains, his courageous ride is only likely to have extended his stay in yellow for 24 hours, as the Tour continues with another day for the climbers on Wednesday. The emotion I had today was not because of the frustrations but because of the pain.