Australian GP: Williams F1 team had no options to stop Vettel

Felipe Massa made a good start in third and maintained the position for the opening stint of the race but he couldn't shake off Vettel, who was never further than one second behind.

Massa pitted on lap 21, losing around 1.5 seconds after exiting behind Red Bull's Daniel Ricciardo, while Vettel stayed out for another four laps to jump ahead of the Brazilian.

However, Smedley said Williams had no other option than to pit Massa when it did and he added the team was surprised by the amount of pace Vettel showed when in clear air.

"If you can follow one second behind, then it means you've got a little bit of pace in hand," said Smedley. "The decision for us then was one-fold really.

"If he managed to get the jump on us [by pitting first] then he would have got out and that would be have been the end of the race for us.

"So the only option for us was to pit first and try and keep him behind - and it wasn't too far away from working.

"The unfortunate thing was he had more pace than what we thought.

"I think he found eight tenths over two laps compared to when he was sat behind Felipe.

"And Felipe lost 1.5 seconds trying to pass Ricciardo - both those things stacked up against us and we ended up behind.

"We took a decision and it didn't come off."