Runaway World Series by Renault championship leader Giedo van der Garde believes traffic cost him the opportunity to score a fourth win in seven races at Silverstone.

Starting the second race of the weekend from the front row of the grid, the Dutchman got a strong start to take a comfortable lead into the opening laps before making his one and only pit-stop on lap ten.

However, while he continued to hold an advantage over second place driver Salvador Duran who pitted at the same time, van der Garde became bottled up behind lapped driver Pablo Sanchez for three laps, costing him time.

It was significant enough for Robert Wickens, who was third in the early stages, to make the most of clear air and pull out a gap big enough to see him pit and return just in front.

Indeed, van der Garde was frustrated to settle for second, speculating that Sanchez's adversity to let him overtake was motivated by his desire for Interwetten Racing team-mate Duran to catch up again.

“For sure it cost me the win,” he told Crash.net Radio after the race. “Sanchez cost me three seconds because I was behind him for three laps and he wouldn't let me pass. I don't know why, maybe because he is Salvador's team-mate, It made all the difference.”

Despite that, van der Garde still comes away from the weekend with an even larger 44 point advantage over second place, now occupied by Duran. As the only driver to finish all seven races in the points this season, van der Garde admits that he is already looking to protect his lead in the coming rounds.

“It is always important to finish the first race and try and win the second race. Hungary is now coming up and I think we will be strong there.”