Valtteri Bottas completed a 'double top' in Friday's incident-hit practice for the Abu Dhabi grand prix when he out-paced Mercedes team-mate Lewis Hamilton under the lights at the Yas Marina Circuit.
The 30-year-old Finn, who was quickest ahead of Red Bull's Max Verstappen in the opening session, followed that up by outpacing six-times champion Hamilton in the later 'twilight' session as Mercedes produced a resounding one-two.
He made good use of a new power unit that had been installed following his engine failure in Brazil and which led to him taking penalties that mean he will start Sunday's race from the back of the grid.
Bottas, who on Thursday announced he was splitting from his wife Emilia, also crashed into Haas's Romain Grosjean late in the second session of an eventful day. Neither driver was hurt.
Bottas produced a best lap in one minute and 36.256 seconds to wind up 1.578 seconds clear of Hamilton, his speed and determination betraying his wish to put the travails of his private life behind him.
After a slow morning, Charles Leclerc was third ahead of his Ferrari team-mate and four-times champion Sebastian Vettel, who arrived late on Friday morning ahead of the session following the birth of his third child, a son, on Wednesday.
The Red Bulls of Max Verstappen and Alex Albon were fifth and sixth ahead of Grosjean, Racing Point's Sergio Perez and the Toro Rosso pairing of Daniil Kvyat and Pierre Gasly.