Hockenheim, Germany - Nico Rosberg, aiming to seize back the championship lead in his home German Formula One Grand Prix, got his weekend off to a strong start by topping the opening practice session on Friday.
Rosberg lapped the 4.5-kilometre long Hockenheim circuit in one minute 15.517 seconds to beat championship leading team mate Lewis Hamilton by 0.326 seconds in a dominant session for Mercedes.
Rosberg conceded the lead in the title battle to rival Hamilton at the last race in Hungary, dropping six points behind the Briton who raced to an unprecedented fifth victory at the Hungaroring.
The German, who won the opening four races but has not stood on the top step of the podium since last month's European Grand Prix, heads into the weekend determined turn the tables back in his favour.
Compatriot Sebastian Vettel set the third fastest-time on his first appearance on home soil as a Ferrari driver.
But the four-times world champion, whose team announced a split with technical director James Allison on Wednesday, was 1.1 seconds adrift of Rosberg's time.
Vettel's team-mate Kimi Raikkonen was fourth ahead of the Red Bull pair of Max Verstappen and Daniel Ricciardo.
They were followed by the McLarens of Fernando Alonso and Jenson Button in seventh and eighth respectively.
The Toro Rosso cars of Daniil Kvyat and Carlos Sainz rounded out the top 10.
Ferrari-backed Frenchman Charles Leclerc took part in his third consecutive Friday morning session for American team Haas, slotting into Mexican Esteban Gutierrez's car.
Mercedes-backed Esteban Ocon, loaned to Renault to be their reserve, was in action in place of Jolyon Palmer.
The youngsters were 17th and 20th on the timing sheets respectively.
Rosberg won the last race at Hockenheim in 2014 and a repeat of that win would put the brakes on Hamilton, who has triumphed in five of the last six races.
It would also hand him a crucial psychological edge over the reigning champion heading into Formula One's annual summer break.
German Grand Prix 1st practice
1. Nico Rosberg (Germany) Mercedes 1:15.517
2. Lewis Hamilton (Britain) Mercedes 1:15.843
3. Sebastian Vettel (Germany) Ferrari 1:16.667
4. Kimi Raikkonen (Finland) Ferrari 1:16.852
5. Max Verstappen (Netherlands) Red Bull - TAG Heuer 1:16.927
6. Daniel Ricciardo (Australia) Red Bull - TAG Heuer 1:17.089
7. Fernando Alonso (Spain) McLaren 1:17.183
8. Jenson Button (Britain) McLaren 1:17.612
9. Daniil Kvyat (Russia) Toro Rosso-Ferrari 1:18.008
10. Carlos Sainz Jr (Spain) Toro Rosso-Ferrari 1:18.044
11. Marcus Ericsson (Sweden) Sauber-Ferrari 1:18.198
12. Valtteri Bottas (Finland) Williams-Mercedes 1:18.210
13. Felipe Massa (Brazil) Williams-Mercedes 1:18.322
14. Romain Grosjean (France) Haas-Ferrari 1:18.589
15. Nico Huelkenberg (Germany) Force India - Mercedes 1:18.591
16. Sergio Perez (Mexico) Force India-Mercedes 1:18.628
17. Charles Leclerc (Monaco) Haas-Ferrari 1:18.882
18. Kevin Magnussen (Denmark) Renault 1:18.933
19. Felipe Nasr (Brazil) Sauber - Ferrari 1:18.961
20. Esteban Ocon (France) Renault 1:18.981
21. Rio Haryanto (Indonesia) Manor-Mercedes 1:19.167
22. Pascal Wehrlein (Germany) Manor-Mercedes 1:19.975
Reuters