Ferrari was left with unanswered questions at the end of the opening day's practice for this weekend's Belgian Grand Prix at Spa-Francorchamps, despite comfortably having held the upper hand over chief rivals McLaren-Mercedes throughout.

Felipe Massa paced the dry morning session to the tune of almost four tenths of a second ahead of team-mate Kimi Raikkonen, with the fastest of the two McLarens - that of Formula 1 World Championship leader Lewis Hamilton - barely able to get within six tenths of a second of the Brazilian.

The 27-year-old then added to that by going second-quickest to former double world champion Fernando Alonso as the rain fell in the afternoon - though he acknowledged afterwards that the inclement conditions had made it difficult to draw any firm conclusions from the day.

"It was an unusual day because of the changing weather," underlined Massa, currently six points adrift of Hamilton in the drivers' title chase but - following his dominant performances in both Budapest and Valencia - incontrovertibly the man with the momentum on his side. "Overall, I am happy with the work we did over the three hours. The car is working well and responds positively to the set-up changes we have made.

"We tried various solutions, and now we must study the data to draw the right conclusions. The tyres worked as we had expected them to; the softer ones seem to offer more performance. I think we are moving in the right direction."

Raikkonen, though - who has been under something of a cloud for much of the middle part of the 2008 campaign, having not now triumphed since Barcelona all the way back in April - came a cropper in the tricky conditions, as he skated off the circuit at turn nine in the afternoon, swiping the circuit barriers as his bid to make it four consecutive Belgian Grand Prix victories did not get off to the most flawless of starts.

"When I went off the track at turn nine, I clipped the kerb and the surface was a bit slippery there because of the rain," the Finn related. "I ended up spinning and then hitting the barrier. Unfortunately, not only did the rear wing break, but the floor was also damaged and it could not be repaired in time. [That was] a shame as already earlier, when I had gone onto new tyres, it had begun raining and I lost a bit of time.

"Let's hope tomorrow morning there's no rain so that I can run more consistently in the dry. In the morning, apart from a few little electrical problems, the car wasn't bad. Tomorrow we will see what we can do, and obviously the weather will be a key factor."

With the battle for championship glory closing in with every race, the entire F1 world is preparing itself for a thrilling showdown, and the Scuderia's team principal Stefano Domenicali knows the epic nature of Spa could well act as the backdrop this weekend to one of the most exciting head-to-heads between Ferrari and McLaren all year.

"All-in-all, it was a day of questions, characterised by rather changeable track conditions," the Italian mused. "We knew the weather here at Spa would play an important role, and today we had first-hand experience of that.

"From what we could understand of the day, taking into account the usual Friday unknowns, the Ferrari barometer is tending more towards good weather - our performance level seems competitive and we are managing to get both types of tyre to work well.

"It was a shame Kimi had an 'off' which lost him some track time, but I don't think this will prove to be a handicap for the rest of the weekend."

"Kimi's off-track excursion meant we were unable to complete the full programme we had planned for him," countered Maranello's technical director Luca Baldisserri. "His car was too damaged to be repaired within the time available.

"Even with the hiccoughs caused by the coming and going of the rain, for his part Felipe was able to complete what we planned for him, picking up some very useful information. Allowing for the fact that track conditions were difficult to understand during these three hours and that temperatures were decidedly on the low side, I think we can be competitive."