Mark Webber took the honours in another rain-hit practice session ahead of Sunday's Belgian Grand Prix.
In the initial 90 minutes only Mercedes duo Michael Schumacher and Nico Rosberg were able to set times before the capricious nature of this region's weather took hold.
The afternoon was a different story as the field enjoyed 55 minutes of relatively dry running at the Spa-Francorchamps circuit prior to the heavens again opening.
Although it eased off and a number of cars returned to the track, the majority settled for their dry times which were never going to be troubled.
Come the conclusion, Webber sat at the top of the timesheet with a lap of one minute 50.321secs, just 0.140secs clear of the Ferrari of Fernando Alonso.
Such times, however, were over four seconds off Webber's pole lap of last year, clearly indicating all the top teams have more in their locker.
The McLaren duo of Jenson Button and Lewis Hamilton were half a second adrift in third and fourth, both Britons only managing nine laps.
Hamilton left it fashionably late before making his entrance, with his best time set on his only lap on the faster soft tyres moments before the rain came down.
Further adrift, but still within a second of Webber, were Ferrari's Felipe Massa and Rosberg before a gap of almost 0.4secs to Sauber's Sergio Perez.
Behind the Mexican were the Force India pair of Nico Hulkenberg and Paul di Resta, the former in the car to the annoyance of Adrian Sutil.
Ordinarily reserve drivers take part in first practice, however, on this occasion Force India opted to reverse the order, leaving Sutil on the sidelines in the afternoon.
That meant the German missed the only true dry running of the day to which he said: "It is not good for the performance to not be in the car.
"It's a bit disappointing what the team has done because it's not good for the success. It was the only dry session we had and I missed it."
As for Di Resta, he was involved in his own dramas as a seemingly innocuous bump into a barrier in FP1 led to more work than had at first been envisaged.
The Scot finally returned to the track midway through FP2, and did enough in his six laps to finish ninth quickest, marginally behind Hulkenberg.
Reigning world champion and current championship leader Sebastian Vettel was forced to settle for 10th spot, 1.469secs behind team-mate Webber, with Schumacher 11th
Bruno Senna, controversially in for Nick Heidfeld for this race and the next in Italy as the German is heading to the High Court in a bid to reclaim his Renault seat, was down in 17th.
That followed a shunt into a barrier in FP1 for the Brazilian who damaged the rear of the car, recovering to finish 3.5secs down, and at least ahead of team-mate Vitaly Petrov who was bottom.
The Russian missed the opportunity to switch to the soft tyres prior to the rain falling and so finished almost 12 seconds behind Webber.