P3: Bottas takes over at Spa

Valtteri Bottas showed the first true glimpse of revitalised Williams' expected strong pace around Spa-Francorchamps by setting the fastest time in a drying Practice Three session.

Although the opening day of the Belgian GP had unusually not been interrupted by rain at any stage, the Ardennes region's notoriously fickle climate awakened on Saturday morning to deliver a wet track for the start of final practice. Predictably, with teams not willing to risk damaging their cars ahead of the all-important later qualifying hour, only a handful of drivers ventured out for timed laps on rain tyres over the first half of the session.

In fact, once Sauber's Esteban Gutierrez had become the first to sample the improving track on slicks, P3 effectively distilled into a 20-minute shootout as all the drivers came out to complete as many laps as possible.

With laptimes tumbling all the time as the grip levels around the undulating 7.004km began to ramp up again, Bottas ultimately emerged on top with a lap of 1:49.465 - the Finn's best time of the weekend so far, but three tenths shy of Lewis Hamilton's impressive benchmark from Friday.

Unusually, neither Mercedes driver finished in the top two of the timesheet as Daniel Ricciardo pipped Nico Rosberg to P2 at the last, although the two W05s undoubtedly remain the favourites for a front-row lockout.

Four-times Spa victor Kimi Raikkonen and Hamilton finished with identical 1:49.817 times, although fourth place went to the Ferrari due to the fact he set his lap first, with Fernando Alonso in sixth in the second F14 T.

Toro Rosso rookie Daniil Kvyat impressed again to take seventh ahead of former Spa winners Jenson Button (McLaren) and Felipe Massa (Williams).

After both drivers missed all of Friday afternoon's running, a truncated session wasn't what either Sebastian Vettel or Pastor Maldonado needed and the pair finished well outside the top ten in 13th and 17th positions respectively.

Ricciardo might have ended the session second but Red Bull are still on the back foot at this power circuit and more signs of their insecurity became apparent during the session.

Both cars took to the track with low downforce wings in order to try and minimise their top-speed disadvantage on Spa's long straights while, to the same end, the World Champions have also played their gear ratio 'joker'.

Teams are allowed one change in 2014 and Red Bull have opted for shorter ratios, mindful of Mercedes' power advantage at both Spa and, as is likely, Monza.