HOCKENHEIM, Germany- Nico Rosberg returned to the top of the time sheets in final practice for his home German GP on Saturday as Mercedes again ended the session clear of the rest.Rosberg, who leads team mate Lewis Hamilton by four points at the halfway stage in the F1 championship, lapped with a best time of 1min17.779 seconds on a baking morning at Hockenheim.DOMINANT TEAM With clear skies and track temperatures approaching 50 degrees Celsius, the German was a considerable 0.601 faster than Hamilton - who set the pace on Friday but looks to have his work cut out in qualifying if he is to beat Rosberg to pole.Mercedes also finished both Friday sessions with their drivers first and second.Ferrari's Fernando Alonso, winner of the last two races held at Hockenheim with the latest in 2012, was third fastest and 0.605 slower than Rosberg despite a spin.Williams drivers Felipe Massa and Valtteri Bottas were fourth and fifth respectively with McLaren's Danish rookie Kevin Magnussen making it five Mercedes-engined cars in the top six.Germany's quadruple world champion Sebastian Vettel, winner at the Nurburgring in 2013, was only ninth fastest with Red Bull team mate Daniel Ricciardo seventh. 3rd and Final Free Practice Session from the F1 German GP at Hockenheimring1. Nico Rosberg (Germany) Mercedes 1min17.779 2. Lewis Hamilton (Britain) Mercedes 1min18.380 3. Fernando Alonso (Spain) Ferrari 1min18.384 4. Felipe Massa (Brazil) Williams-Mercedes 1min18.575 5. Valtteri Bottas (Finland) Williams-Mercedes 1min18.611 6. Kevin Magnussen (Denmark) McLaren 1min18.756 7. Daniel Ricciardo (Australia) Red Bull - Renault 1min18.769 8. Kimi Raikkonen (Finland) Ferrari 1min18.842 9. Sebastian Vettel (Germany) Red Bull - Renault 1min18.890 10. Nico Hulkenberg (Germany) Force India - Mercedes 1min19.127 11. Daniil Kvyat (Russia) Toro Rosso - Renault 1min19.131 12. Jean-Eric Vergne (France) Toro Rosso - Renault 1min19.470 13. Jenson Button (Britain) McLaren 1min19.489 14. Sergio Perez (Mexico) Force India - Mercedes 1min19.505 15. Esteban Gutierrez (Mexico) Sauber - Ferrari 1min19.601 16. Romain Grosjean (France) Lotus - Renault 1min20.078 17. Jules Bianchi (France) Marussia - Ferrari 1min20.198 18. Pastor Maldonado (Venezuela) Lotus - Renault 1min20.466 19. Adrian Sutil (Germany) Sauber - Ferrari 1min20.844 20. Kamui Kobayashi (Japan) Caterham - Renault 1min21.018 21. Marcus Ericsson (Sweden) Caterham - Renault 1min23.077 22. Max Chilton (Britain) Marussia - Ferrari 1min23.449Stay with Wheels24 for the 2014 German GP this weekend.