Lewis Hamilton edged out teammate Nico Rosberg as Mercedes took command of the first German Grand Prix practice session.
The Briton finished more than one second clear of the entire field bar Rosberg, with whom he traded fastest laps as the squad hit the front at the halfway stage. Hamilton eventually settled the fight with a 1m31.754s which put him two tenths clear of Rosberg, victorious last time out at Silverstone.
Red Bull's Mark Webber prevailed in what was a much tighter fight for third, eclipsing the lead Force India of Adrian Sutil by just 0.033sec.
Kimi Raikkonen, Felipe Massa and Jenson Button all got within four tenths of Webber's time. Despite Massa's pace it was an unhappy session for Ferrari, however, as Fernando Alonso failed to complete a lap due to electrical issues.
The Spaniard lost power and abandoned his car just four minutes into the session, and then suffered an almost identical failure 40 minutes later on what was his second attempt at a first installation lap. This time he was at least able to revive the car and return to the pits, but was unable to return and ended the session with just two aborted laps under his belt.
Sebastian Vettel, Alonso's chief championship rival, ended the session in eighth ahead of Romain Grosjean, who slipped in front of Sergio Perez and Paul di Resta as the checkered flag fell.
Pos Driver Team Time Gap Laps
1. Lewis Hamilton Mercedes 1m31.754s 25
2. Nico Rosberg Mercedes 1m31.973s + 0.219s 25
3. Mark Webber Red Bull-Renault 1m32.789s + 1.035s 22
4. Adrian Sutil Force India-Mercedes 1m32.822s + 1.068s 16
5. Kimi Raikkonen Lotus-Renault 1m32.956s + 1.202s 22
6. Felipe Massa Ferrari 1m33.065s + 1.311s 18
7. Jenson Button McLaren-Mercedes 1m33.139s + 1.385s 24
8. Sebastian Vettel Red Bull-Renault 1m33.213s + 1.459s 20
9. Romain Grosjean Lotus-Renault 1m33.260s + 1.506s 27
10. Sergio Perez McLaren-Mercedes 1m33.456s + 1.702s 18
11. Paul di Resta Force India-Mercedes 1m33.493s + 1.739s 18
12. Nico Hulkenberg Sauber-Ferrari 1m33.810s + 2.056s 20
13. Daniel Ricciardo Toro Rosso-Ferrari 1m33.901s + 2.147s 23
14. Jean-Eric Vergne Toro Rosso-Ferrari 1m33.976s + 2.222s 26
15. Pastor Maldonado Williams-Renault 1m34.025s + 2.271s 20
16. Valtteri Bottas Williams-Renault 1m34.200s + 2.446s 22
17. Esteban Gutierrez Sauber-Ferrari 1m34.437s + 2.683s 24
18. Charles Pic Caterham-Renault 1m35.674s + 3.920s 23
19. Max Chilton Marussia-Cosworth 1m35.987s + 4.233s 19
20. Giedo van der Garde Caterham-Renault 1m36.078s + 4.324s 23
21. Rodolfo Gonzalez Marussia-Cosworth 1m37.459s + 5.705s 21
22. Fernando Alonso Ferrari no time 2