Nico Rosberg completed a clean sweep of practice sessions as he led the way during Saturday morning’s running at the German Grand Prix.
Rosberg clocked a time of 1:15.738 on his second run on Super Soft tyres to inch 0.057s clear of Mercedes team-mate Lewis Hamilton at Hockenheim.
Hamilton’s best time came on the first runs on the Super Softs and he was unable to respond to Rosberg’s improvement.
Hamilton has also been summoned to the stewards over an alleged unsafe release in the pit lane.
Red Bull and Ferrari moved closer to Mercedes, as Daniel Ricciardo lapped within 0.099s of Rosberg’s best, while Kimi Räikkönen was 0.164s behind the local driver.
Sebastian Vettel and Max Verstappen were fifth and sixth, as Vettel returned to the pits with a wobbly front wing at the end of the session, while the Dutchman earlier complained that his battery was not re-charging.
Williams improved compared to their Friday effort with Valtteri Bottas and Felipe Massa the only other drivers to lap within a second of Rosberg’s time.
Fernando Alonso took ninth for McLaren as Force India’s Nico Hülkenberg completed the top 10.
Carlos Sainz Jr. and Daniil Kvyat were 11th and 14th for Toro Rosso, split by the Mexican pairing of Sergio Pérez and Esteban Gutiérrez.
Kevin Magnussen and Jolyon Palmer took 15th and 16th for Renault, in front of the Sauber duo of Marcus Ericsson and Felipe Nasr.
McLaren's Jenson Button had a low-key session after a precautionary trip to hospital in Mannheim on Friday amid an eye complaint.
Button, who was quickly given the all-clear by medical staff, set the 19th best time after completing only six laps, ahead of Manor’s Pascal Wehrlein and Rio Haryanto.
Romain Grosjean amassed only four laps before he spun exiting Turn 3, amid complaints about his gearbox.
Grosjean returned to the pits at slow speed and Haas diagnosed a problem, meaning he will drop five places on the grid due to an unscheduled gearbox change.