The British rider went solo with around 10km to race, after she'd been in a two rider breakaway for several kilometres previous to her winning move.
Despite the best efforts of the chasers, Armitstead's lead only increased as she raced towards the finish line.
With four kilometres to go she had pushed her advantage out to 37 seconds and from there it looked like the win would be hers.
Armitstead's Boels Dolmans teammate Chantal Blaak won the sprint for second and Tiffany Cromwell (Canyon-SRAM) rounded out the podium.
Riders to watch this year
Coverage of the women's race was lacking, with no live television available despite the final 100+ km of the men's race being shown.
Whilst Armitstead was riding to her first win in the rainbow stripes of the world champ, the men's race was a sedate affair with a break being managed between 1-50 and 3-30 ahead.
The men's race did liven up, and Greg Van Avermaet took the win ahead of Peter Sagan.
Thank you for reading 20 articles this month* Join now for unlimited access
Enjoy your first month for just £1 / $1 / €1
*Read 5 free articles per month without a subscription
Join now for unlimited access
Try first month for just £1 / $1 / €1