Lewis Williamson says team decided he shouldn't make mandatory pitstop in Spa Formula Renault 3.5 race

The Red Bull-backed Arden Caterham driver was running in the lead group early in the race, but his chances of a good result were destroyed when the safety car was deployed just as he was about to make a pitstop.

As championship rules declare that the pits are closed when the safety car takes to the track, Williamson had to abort as he was heading for the pit entry.

The race was then red-flagged, and when it started again the Scot was in the lead as one of four drivers yet to pit. He and ISR driver Jake Rosenzweig did not come in for a mandatory stop in the final laps, meaning they were first to take the chequered flag.

Both had 60 seconds added to their race time just before the end of the race, leaving Kevin Magnussen - the leader of the cars that had stopped - as the winner.

"When I went to pit I got told at the last second that the safety car was out and we couldn't pit," Williamson told AUTOSPORT. "After the restart I tried to get my head down and do some good laps.

"Towards the end I asked when the team wanted me to box and they said they had taken the decision not to pit. They just told me to run to the finish, get a feel for the car and come back with some feedback for them."

Williamson added that he had no problem with the decision taken on the pitwall.

"Once the safety car was out our race was done anyway," he said.