Hosking had just enough speed to take the win over Dutchwoman Kirsten Wild (Argos-Shimano) who has so far claimed 13 victories this season, and American Shelly Olds (Tibco to the Top).
It was a relieved Hosking after the 120km stage and seven podiums so far in 2013.
"It's been a long time between wins for me and I'm really so happy to get the win today," an ecstatic Hosking said after the race.
"I've had a lot of podiums but winning is really just a different feeling.
"The girls all rode really well today and it feels so good to pull off the win for them," she added.
Hosking was well protected by Emilie Moberg and sat on the wheel of Wild until 150 metres to go when the 22-year-old said she put her "head down and hoped for the best."
Get The Leadout Newsletter
The latest race content, interviews, features, reviews and expert buying guides, direct to your inbox!
Saturday's stage was the last chance for the sprinters ahead of Sunday's final stage through Valkenberg, with Hitec team manager Karl Lima pleased with the result.
"In the past two days our two sprinters Hosking and Moberg have shown they can beat anybody in a bunch sprint, alternating to lead out for each other. I'm very happy," Lima said.
Moberg won the field sprint for third place on Friday's stage, ahead of Olds and Wild.
