Lewis Hamilton topped the opening practice session for the final race of the 2016 season in Abu Dhabi, as the Briton aims to claim his fourth title this weekend, but faces an uphill battle against Mercedes team-mate Nico Rosberg.
Rosberg who could claim his first ever title by finishing in the top three, was second quickest, +0.374s adrift of Hamilton – who was the only driver to dip below the 1m43s barrier.
Red Bull once again look to be Mercedes' closest rivals, with Max Verstappen finishing third ahead of team-mate Daniel Ricciardo, with just half a tenth between them, but more importantly, Verstappen was well within a tenth of Rosberg's time.
Sebastian Vettel completed the top five for Ferrari ahead of Force India's Segio Perez as they look to cement fourth in the constructors' standings this weekend.
Kimi Raikkonen was seventh from Toro Rosso's Carlos Sainz, Williams' Felipe Massa and Sauber's Marcus Ericsson in an impressive tenth.
Alfonso Celis Jr, in for Nico Hulkenberg, finished just three-tenths adrift of Perez in the sister Force India, whilst rookie stand-in Jordan King was a second behind Manor's Pascal Wehrlein.
Daniil Kvyat propped up the table in last place after suffering a puncture which curtailed his running.