SPA, Belgium (AP) -- Lewis Hamilton posted the fastest time in the second practice of the Belgian Grand Prix on Friday, finishing ahead of Mercedes teammate Nico Rosberg as their positions from the morning session were reversed.
Conditions were cool and overcast for both runs, although the rain stayed away on the 7-kilometer (4.3-mile) Spa track -- the longest on the calendar.
Times were faster in the afternoon, with Hamilton completing 26 laps and clocking a best lap of 1 minute, 49.189 seconds -- more than half a second faster than Rosberg, who stayed out for two laps longer.
The F1 championship resumed this weekend following a summer break, with Rosberg leading Hamilton by just 11 points. The Briton leads Rosberg 5-4 in race wins this season, but has retired from two races.
Two-time F1 champion Fernando Alonso was third quickest both times in his Ferrari.
Four-time defending champion Sebastian Vettel sat out the second session because of a power unit failure due to an electrical problem in the morning, where he finished nearly two seconds behind Rosberg in 11th.
The red flag came up twice in the afternoon session. Venezuelan driver Pastor Maldonado lost control of his Lotus and Mexican Esteban Gutierrez stalled his Sauber.
Vettel, who finished second in qualifying at the Hungarian GP last month, could not even get his Red Bull out of the garage.
It has been a miserable season so far for the German driver, with only two podium finishes and no pole positions. He has retired from three races and is down in sixth place overall. Quite a contrast to last year, when his victory in Spa was the first of nine straight wins.
But this campaign has seen him lag behind teammate Daniel Ricciardo, who has won two races since switching from Toro Rosso in the offseason and is third in the standings -- although he trails Hamilton by 60 points.
Rosberg clocked 1:51.577 seconds in the morning and Hamilton, the 2008 champion, managed a best of 1:51.674.
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