Title contender Lewis Hamilton prepared for his 200th Formula One race with the fastest time in Belgian Grand Prix practice before rain brought an early end to the day's action.
The Mercedes driver, who can equal Michael Schumacher's all-time record of 68 pole positions in Saturday's qualifying, lapped the longest track on the calendar with a best time of one minute 44.753 seconds.
Ferrari's Kimi Raikkonen, who had been fastest in the morning session with a time of 1:45.502 on ultra-soft tyres while Hamilton stayed on softs, was second on the timesheets with an afternoon best that was 0.262 slower than the Briton.
Hamilton also used the ultra-softs to set his best time before the rain set in with 20 minutes remaining.
Valtteri Bottas, Hamilton's team mate, made it two Finns in the top three while Red Bull's Dutch teenager Max Verstappen kept his travelling orange army of fans happy with fourth in both sessions.
Verstappen was fastest in last year's Friday practice, and went on to put his Red Bull on the front row, but the new cars are significantly faster and Hamilton was more then three seconds quicker.
Ferrari's world championship leader Sebastian Vettel was third and fifth, just 0.01 slower than Verstappen, respectively, in Friday's sessions.
Vettel leads Hamilton by 14 points with nine rounds remaining and both men on four wins apiece.