Michelton-Scott rider Kennedy had broken away from the peloton and looked to be heading for her first Women's World Tour win in Piedicavallo, Italy.

But Dutch rider Marianne Vos had other ideas and sped through in the final metres to clinch victory.

"Lesson most definitely learnt," Kennedy said on Twitter.

"Always sprint beyond the line and never celebrate early."

For Vos, it was a second consecutive Giro Rosa stage win, while Kennedy was forced to settle for second place as Denmark's Cecilie Uttrup Ludwig took third.

However, second place still marked a first World Tour podium finish for the Australian.

"Right at the end, I looked back and thought I had it, my first World Tour win but as I raised my fist in the air, Vos came past me. I was absolutely spent," Kennedy said.

"Obviously I am very very disappointed to miss out but it is still my best result. I haven't had a World Tour podium before so I can be really happy with that."

Victory for Vos means she moved up to third in the general classification, behind Ludwig in second and Poland's Katarzyna Niewiadoma, who has the overall lead.

"Lucy had a great attack and she had a good lead," Vos said.

"She was on the cobbles and there were only two lines we could take in between the cobbles, she was on the right side,

"I was on the left and I had slightly more speed, so she put her arm in the air and I came around in the last five metres, so for her that was pretty sad. I told her not to do that again."

Kennedy (left) goes early with her celebrations

Vos (right) comes from out of nowhere to take it on the line