The Dutchman won the 194.9km race in a sprint finish in Aartselaar with his Rabobank team-mate Kenny Van Hummel, last year’s winner, finishing second. Australia’s Mark Renshaw came third.
After 20km the race was led by a group of four riders, Kurt Hovelijnck, Quentin Bertholet, Olivier Pardini and Jeroen Lepla.
Argos Shimano and Rabobank worked hard on the front of the peloton and caught Bertholet and Pardini.
And 10km from the finish, Hovelijnk and Lepla were caught to set up a sprint finish where Bos picked up his second victory in five days after winning the World Ports Classics on Saturday.
Kenneth Vanbilsen was the first Belgian across the line in seventh place.