Barrichello hopes turnaround has begun

The squad took a clear step forward in Valencia, with both cars qualifying in the top ten, and Barrichello gaining ground on the first lap and during the safety car pitstops, then fending off Robert Kubica to secure fourth.

"It was great fun out there today and the car was behaving well throughout the race," said Barrichello.

"We really seem to be heading in the right direction with the development of the car and I hope that this improved performance continues for the rest of the season."

Williams looked set to get two cars in the points, with Nico Hulkenberg holding 10th despite losing ground waiting behind Barrichello in the pits. But the German had to retire with an exhaust failure late in the race.

"That was a good performance today by both cars, and definitely a step forward," said the team's technical director Sam Michael.

"Unfortunately, an exhaust failure cost Nico a possible point today and we will be investigating the cause back at the factory."