Felipe Massa and Fernando Alonso top Spa standings

Felipe Massa and Fernando Alonso topped the timesheets in Friday's dual practice sessions ahead of the Belgian Grand Prix in Spa.

Massa confirmed Ferrari's dominance in Spa with a lap of one minute 47.284 seconds - the fastest of the day.

But it was Renault's Alonso who topped the timesheets in 1:48.454 in a rain-interrupted second practice, which was stopped when Giancarlo Fisichella spun.

McLaren's Lewis Hamilton finished third in the first session and then fourth.

Massa is six points behind Hamilton in the drivers' standings and is looking to close the gap by building on his victory in Valencia two weeks ago.

The Brazilian was in a class of his own in the first practice session; knocking out fastest lap after fastest lap in the closing stages as team-mate Kimi Raikkonen and Hamilton were unable to close him down.

After a spell of testing in Monza, Ferrari believe they have ironed out their technical problems and are ready to launch a renewed attack on the drivers' title.

Ferrari's defending world champion Raikkonen is hoping to use his experience at Spa, where he has won the last three Grands Prix, to propel himself back into the title race.

But the Finn's run of bad luck continued in the second session, when he spun, slid into a tyre wall and dislodged his rear wing.

He finished fifth overall to follow up his second place in first practice.

Soon afterwards, Fisichella spun coming out of a patch of standing water and crashed into a metal barrier before bringing his Force India to a halt on the grass.

The session was then halted for 10 minutes to remove Fisichella's car while officials brushed away the water.

Australian Mark Webber was also caught out by a shower in the second session as he slid into the barriers at Rivage, while Renault's Nelson Piquet also lost his rear wing.

Alonso looked to be taking advantage of a lighter fuel load as he finished top of the timesheets, just 0.050 secs ahead of Massa.

The McLarens of Heikki Kovalainen and Hamilton followed the Brazilian home in a reversal of their placings from first practice.

Nonetheless, Hamilton remains confident that he can challenge the Ferraris for a race victory on Sunday in wet or dry conditions.

"This track is a great challenge in the dry, but in the wet it will be so tricky for everyone," the 23-year-old said.

"We're going for the win. We're just as competitive as them. We're pretty much equal with them.

"They have a bit more speed at the end of the straight, but I don't think it will make any difference.

Overall, six drivers - Massa, Raikkonen, Hamilton, Kovalainen, Alonso and Webber - set quicker times in the morning run than Alonso in the afternoon.

The two sessions, one played out in overcast, chilly conditions and the other affected by sudden rain, proved just how changeable the conditions in Spa can be and underlined their importance in determining the outcome of Sunday's race.

The drivers return to the winding track through the Ardennes Forest for final practice and then qualifying at 1300 BST on Saturday.