FP3 - Bottas puts Williams on top as rain hits Spa-Francorchamps

Valtteri Bottas thrust Williams to the fore at Spa-Francorchamps on Saturday morning as he beat Red Bull's Daniel Ricciardo and Mercedes' Nico Rosberg to the top spot in the third and final practice session.

It took a while for the session to get started as the field waited for the track to dry out following early morning rain, but as conditions gradually improved so did track activity, culminating in a flurry of fastest laps in the closing minutes.

It was Bottas who emerged on top, the Finn throwing Williams' hat into the ring with 1m 49.465s to take the fastest time by more than a quarter of a second.

And it was not a Mercedes that was second; that honour fell to Daniel Ricciardo as he wheeled his Red Bull round in 1m 49.733s to beat Nico Rosberg by 0.006s.

Behind them, Kimi Raikkonen - who had at one stage been fastest - ended up fourth on 1m 49.817s from Lewis Hamilton on the exact same time. The Briton had earlier demoted Rosberg by just 0.001 seconds. Fractionally further down the road were Fernando Alonso on 1m 49.890s and Daniil Kvyat on 1m 49.893s, for Ferrari and Toro Rosso respectively.

Jenson Button's strong McLaren form continued as he went eighth fastest on 1m 50.203s, which pushed Felipe Massa's Williams down to ninth on 1m 50.423s.

Jean-Eric Vergne's Toro Rosso was next on 1m 50.535s ahead of Sergio Perez's Force India on 1m 50.592s, Kevin Magnussen's McLaren on 1m 50.748s and Sebastian Vettel's Red Bull on 1m 50.814s. The world champion, incidentally, is using his Hungarian engine after yesterday's ignition problems required a change of power unit.

Nico Hulkenberg was 14th in the second Force India on 1m 50.866s from Adrian Sutil's Sauber on 1m 50.962s, as Romain Grosjean slipped down the order to 16th on 1m 51.509s ahead of Lotus team mate Pastor Maldonado on 1m 51.610s and Esteban Gutierrez who lapped his Sauber in 1m 51.898s.

Jules Bianchi took his Marussia round in 1m 52.457s, with team mate Max Chilton close behind on 1m 54.984s, while Marcus Ericsson's Caterham recorded 1m 54.294s to better debutant partner Andre Lotterer, who completed the field in 1m 55.008s.

Whether this order at the front will remain after qualifying remains to be seen, and could depend on whether it rains again - with showers currently forecast to hit the track at the same time the shootout is set to begin.