The German, who started tenth on the grid, owed much to his team's pit strategy for the result, as he emerged in the lead after everyone had made their mandatory stops.
Adrian Valles crowned off his excellent weekend by taking second with a final corner manoeuvre on Damien Pasini. Valles had been hounding the Cram Competition driver since he had emerged ahead of him after the pitstops. At the final Goddards hairpin on the last lap, Valles dived inside Pasini sending him off the circuit.
Valles took the position and Pasini crawled over the line in third, ahead of Tristran Gommendy.
Championship leader Robert Kubica's damage limitation exercise was effective - the Polish driver securing sixth after starting at the back of the grid because of an anti-roll bar infringement.
However, several other leading drivers were eliminated from the race following a series of accidents.
Pole-sitter Eric Salignon was involved in a first corner accident with Jaap Van Lagen and Christian Montanari.
Van Lagen got the jump at the start, and Salignon ran wide onto the grass. When the Frenchman rejoined the track he collided with Van Lagen, who in turn collected Montanari.
Carlin Motorsport teammates Will Power and Andreas Zuber committed motorsport's cardinal sin by taking each other out. Zuber had just left the pits and Power dived inside to pass Austrian. The pair touched and they both spun backwards into the gravel.
The 2015 Formula Renault 3.5 season will be notable for being the last with the French company's backing but also produced a worthy champion in Oliver Rowland. PETER MILLS evaluates this year's crop of drivers
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Landing the Fortec seat that took rising star Robin Frijns to the 2012 FR3.5 title was already a good sign for Stoffel Vandoorne. Then McLaren took him under its wing. Peter Mills tells Vandoorne's story so far