Ferrari's on-form Felipe Massa set the pace in Belgian Grand Prix free practice on Friday while team mate Kimi Raikkonen again looked out of sorts.

Brazilian Massa, six points behind McLaren's Lewis Hamilton in the championship after winning in Valencia last month, dominated a chilly and overcast morning session with a lap of one minute 47.284 seconds.

He was then second in the afternoon, just 0.050 slower than Renault's former champion Fernando Alonso's quickest lap of 1:48.454.

World champion Raikkonen, winner of the last three races in Belgium but without a victory since the end of April, was second quickest in the morning in 1:47.623 but spun off into the barriers after lunch when a light drizzle descended.

The Finn nursed his stricken car back to the pits without the broken rear wing that had fallen off in the middle of the track.

Italian Giancarlo Fisichella also crashed his Force India and the session was then stopped for 10 minutes while marshals scrubbed fluid off the circuit.

The daunting high-speed track is Raikkonen's favourite but he needs to beat Massa this weekend to get back into the reckoning and prevent Ferrari from putting all their weight behind the Brazilian's title challenge.

Hamilton, the 23-year-old Briton who is 13 points clear of Raikkonen with six races remaining, was third in the morning ahead of Finnish team mate Heikki Kovalainen. The two reversed their positions in the second session.

Germany's Adrian Sutil, whose Ferrari-powered Force India team have yet to score a point, was a surprising eighth fastest with a quick lap right at the end of the afternoon before the skies opened.

Honda made a nightmare start to their weekend in the Ardennes forests, with Jenson Button and Rubens Barrichello occupying the last two slots on the timesheets and more than three seconds off the pace.

Australian Mark Webber was a casualty of a shower midway through the second session, his Red Bull sliding off into the barriers at Rivage, while Renault's Nelson Piquet also lost his rear wing.

First free practice session times for the Belgian Grand Prix:

1. Felipe Massa (Brz) Ferrari 1 min 47.284 secs

2. Kimi Raikkonen (Fin) Ferrari 1:47.623

3. Lewis Hamilton (GB) McLaren-Mercedes 1:47.878

4. Heikki Kovalainen (Fin) McLaren-Mercedes 1:47.932

5. Fernando Alonso (Spn) Renault 1:48.104

6. Mark Webber (Aus) Red Bull-Renault 1:48.428

7. Sebastien Bourdais (Fra) Toro Rosso-Ferrari 1:48.557

8. Sebastian Vettel (Ger) Toro Rosso-Ferrari 1:48.958

9. Timo Glock (Ger) Toyota 1:48.997

10. Nelson Piquet (Brz) Renault 1:49.068

11. Robert Kubica (Pol) BMW Sauber 1:49.139

12. Nick Heidfeld (Ger) BMW Sauber 1:49.185

13. Nico Rosberg (Ger) Williams-Toyota 1:49.611

14. Jarno Trulli (Ita) Toyota 1:49.625

15. David Coulthard (GB) Red Bull-Renault 1:49.849

16. Giancarlo Fisichella (Ita) Force India-Ferrari 1:49.986

17. Adrian Sutil (Ger) Force India-Ferrari 1:50.117

18. Kazuki Nakajima (Jpn) Williams-Toyota 1:50.125

19. Jenson Button (GB) Honda 1:50.464

20. Rubens Barrichello (Brz) Honda 1:50.905

Second free practice session times for the Belgian Grand Prix:

1. Fernando Alonso (Spn) Renault 1 min 48.454 secs

2. Felipe Massa (Brz) Ferrari 1:48.504

3. Heikki Kovalainen (Fin) McLaren-Mercedes 1:48.740

4. Lewis Hamilton (GB) McLaren-Mercedes 1:48.805

5. Kimi Raikkonen (Fin) Ferrari 1:49.328

6. Nico Rosberg (Ger) Williams-Toyota 1:49.405

7. Sebastian Vettel (Ger) Toro Rosso-Ferrari 1:49.427

8. Adrian Sutil (Ger) Force India-Ferrari 1:49.585

9. Jarno Trulli (Ita) Toyota 1:49.715

10. Nick Heidfeld (Ger) BMW Sauber 1:49.725

11. Robert Kubica (Poland) BMW Sauber 1:49.875

12. David Coulthard (GB) Red Bull-Renault 1:49.922

13. Sebastien Bourdais (Fra) Toro Rosso-Ferrari 1:49.948

14. Timo Glock (Ger) Toyota 1:50.281

15. Kazuki Nakajima (Jpn) Williams-Toyota 1:50.364

16. Giancarlo Fisichella (Ita) Force India-Ferrari 1:50.740

17. Jenson Button (GB) Honda 1:50.925

18. Rubens Barrichello (Brz) Honda 1:51.238

19. Nelson Piquet (Brz) Renault 1:51.334

20. Mark Webber (Aus) Red Bull-Renault 1:51.640