Vos takes remarkable fourth stage win of the race, while Van Vleuten defended her overnight GC lead to take her second consecutive Giro Rosa title.
Van der Breggen survives two attacks from van Vleuten to take stage win on tough summit finish.
The British rider attacked from a reduced group to solo home, while Van Vleuten comfortably held her overall lead.
Annemiek van Vleuten won Wednesday's stage 6 individual time trial, padding her lead in the overall
Though she often finds herself pitted against Anna van der Breggen, Annemiek van Vleuten says their relationship is good, that the rivalry enhances women's cycling.