A sizeable group of six riders headed up the road early on a difficult final-day parcours - Danail Petrov (Caja Rural), Bjorn Tore Hoem (Team PlussBank), Sep Vanmarcke (Blanco Cycling), Adrian Palomares (De Rijke), Vladimir Isaychev (Katusha) and Remi Pauriol (Sojasun) making up the move.
Team Sky kept the break on a short leash with Bernhard Eisel marshalling things as Thomas Degand (Accent Jobs) and Sander Armee (Topsport Vlaanderen-Beloise) headed off to link up with the escapees on the four laps around Honefoss.
Team Saxo-Tinkoff hit the front on the final loop in a bid to set things up for Paulinho but Team Sky resumed control on the climb around the back of the course. The steep ramps saw the peloton split briefly but Boasson Hagen had Luke Rowe and Josh Edmondson for support before things came back together.
With 12km to go Lars-Petter Nordhaug (Blanco Cycling) hit out as the peloton split significantly once again, seventh-placed Jesper Hansen (Cult Energy) also jumping clear to create a dangerous move which was dragged back.
It was Edmondson who drove on into the final kilometre as the sprint took hold and Boasson Hagen kept it upright to clinch yellow.
