Nico Rosberg topped Saturday morning practice for the Japanese Grand Prix while his Formula 1 title rival Lewis Hamilton crashed.
Rosberg had lapped three-tenths slower than Hamilton while both were running on the slower hard-compound Pirelli tyres early in the session.
The German completed his qualifying simulation on medium rubber first, improving by 1.3s to take top spot.
Moments later, Hamilton started his flying lap, but carried too much speed into Turn 1, ran wide onto the asphalt runoff and couldn't avoid going head on into the tyre barrier.
The front-left corner of his Mercedes was damaged in the crash but although Hamilton did not set a time on the faster tyre, his pace on the hard Pirellis was still good enough to be second fastest, albeit one second down on Rosberg.
Fernando Alonso was best-of-the-rest in third place, 1.211s off the pace, even though the Ferrari driver didn't put together a perfect lap.
Williams pairing Felipe Massa and Valtteri Bottas both completed their qualifying simulations late in the session to take fourth and fifth fastest ahead of Daniel Ricciardo.
The Australian was unable to make a big improvement on the medium rubber, finding less than three-tenths, with a wide moment at Degner costing him time.
Kevin Magnussen was seventh fastest ahead of the two Toro Rossos, with Jean-Eric Vergne outpacing 2015 Red Bull driver Daniil Kvyat by less than half-a-tenth.
Jenson Button completed the top 10 ahead of Nico Hulkenberg and Kimi Raikkonen - with the Finn losing track time towards the end as Ferrari decided to change his engine.
Several drivers hit trouble during the session, with Red Bull driver Sebastian Vettel, fresh from the revelation that he will leave the team at the end of the year, completing only six laps and ending up 15th.
Esteban Gutierrez also had a big moment, losing the rear of his Sauber exiting 130R and spinning, the Mexican just keeping it out of the barrier.
Team-mate Adrian Sutil also had an off, spinning at the chicane, with the two Sauber drivers ending up 14th and 18th respectively.
Both Lotus drivers also had similar offs to Hamilton by running wide exiting Turn 1, potentially as a consequence of a tail-wind blowing into that corner, but Pastor Maldonado and Romain Grosjean were able to keep their cars out of the wall and continue.
At the back, Marcus Ericsson was again the quickest of the Caterham and Marussia drivers in 19th place, half-a-second faster than Max Chilton.
|6||Daniel Ricciardo||Red Bull/Renault||1m35.086s||1.858s||13|
|8||Jean-Eric Vergne||Toro Rosso/Renault||1m35.494s||2.266s||8|
|9||Daniil Kvyat||Toro Rosso/Renault||1m35.538s||2.310s||17|
|11||Nico Hulkenberg||Force India/Mercedes||1m35.732s||2.504s||15|
|13||Sergio Perez||Force India/Mercedes||1m36.365s||3.137s||8|
|15||Sebastian Vettel||Red Bull/Renault||1m36.460s||3.232s||6|