Vos finished a disappointing 10th at the World Championships road race in Ponferrada, Spain, Saturday, the worst Worlds performance of her decorated career. The normally imperious Olympic champion has been consistent throughout her career and in eight previous appearances at the World Championships, had never finished below second, as well as winning three times.
She was also a track Olympic champion in 2008 and is a seven-time cyclo-cross world champion. On the road she has won the women's Giro d'Italia three times and finished overall World Cup champion five times.
Yet despite being part of a four-woman breakaway over the top of the final climb in Ponferrada with just three kilometres to the line, she failed to turn that situation to her advantage and faded in an eventual sprint finish between 15 women.
The woman that went on to win however, Pauline Ferrand-Prevot, denied the result indicated a waning in Vos's powers.
"I don't think so, everybody wants to beat Marianne so I think it's quite hard for her," said the 22-year-old, a Rabo Liv team-mate of the Dutchwoman's.
"I learnt a lot from Marianne these last three years. It's not a victory for her but I think she's also happy for me."
Ferrand-Prevot also revealed that in the sprint finish she had tucked in behind Vos to use the 27 year old, known as the "Cannibal", to launch her own strike for the line, just as she had done when she won the prestigious La Fleche Wallonne Feminine in April.
"Already in Huy (the final climb at Fleche) I was in the wheel of Marianne, so I knew it was a good wheel for the sprint," she added.
Sweden's Emma Johansson, who took bronze in a photo-finish behind Germany's Lisa Brennauer, who also won the timetrial title on Tuesday, said Vos remained the woman to beat despite this set-back.
But Johansson, who was second to Vos last year and took a bronze behind Italy's Giorgia Bronzini and Vos in 2010, said that a result like this could only be good for women's cycling.
"Marianne is a really strong and awesome rider, she can do everything," said Johansson.
"I think, actually, it might not be bad for women's cycling to move around a bit, to have new, stronger, younger riders coming up.
"It's nice to have someone else in that world champion's jersey. I'm a bit surprised but she was up there and will still be strong.
"I've seen she's beatable and that showed today. It's good for us to see that's possible, it's very nice."