Valtteri Bottas maintained his impressive form with fastest time in second practice for the Spanish Grand Prix on Friday.
The Finn, who leads the drivers' championship by one point from Mercedes-GP teammate Lewis Hamilton, had been quickest in the first session and he backed that up with a lap of 1 minute, 17.284 seconds in the afternoon.
That was 0.049 seconds ahead of Hamilton, who improved after being 0.6 seconds off the pace in the morning.
Mercedes, who have had one-two finishes in the first four races, appear on track to make it five in a row as they held the edge over Ferrari.
Charles Leclerc was third, but 0.3 off Bottas, with the second Ferrari of Sebastian Vettel fractionally slower.
Max Verstappen, who had an engine change after problems in first practice, was fifth quickest in his Red Bull Racing car, with Romain Grosjean completing the top six.
It was a dismal day for Renault though. A new spec engine did little to improve their performance with Nico Hulkenberg and Daniel Ricciardo 14th and 15th fastest respectively.
Final practice is at 2pm UAE time, with qualifying at 5pm. The 66-lap race begins at 5.10pm.