Nico Rosberg maintained his momentum by setting the pace ahead of team-mate Lewis Hamilton in an ominous first practice session from Mercedes at the Bahrain Grand Prix on Friday.
Rosberg followed up winning the last three races of last season by taking the chequered flag in the season-opening Australian Grand Prix last month.
The German is aiming to extend his best run of consecutive Formula One wins to five on Sunday and made a positive start in Sakhir, clocking one minute, 32.294 seconds to top the timesheets.
Hamilton's fastest lap was 0.505 seconds slower than the German in a session which saw the Mercedes duo complete 24 laps apiece.
Brit Hamilton completed a clean sweep on the first day of free practice at Albert Park, but was second when it mattered on Sunday and the world champion is eager to get back on top of the podium this weekend.
Ferrari's Kimi Raikkonen (1:34.128) was third in FP1 ahead of Red Bull duo Daniel Ricciardo and Daniil Kvyat as Mercedes once again set their stall out for the weekend in the desert.
Sebastian Vettel was only 11th fastest, while debutant Stoffel Vandoorne was down in 18th after the McLaren reserve driver was drafted in to replace the injured Fernando Alonso.
1. Nico Rosberg (Mercedes) 1:32.294
2. Lewis Hamilton (Mercedes) 1:32.799
3. Kimi Raikkonen (Ferrari) 1:34.128
4. Daniel Ricciardo (Red Bull) 1:34.461
5. Daniil Kvyat (Red Bull) 1:34.541
6. Nico Hulkenberg (Force India) 1:34.601
7. Carlos Sainz (Toro Rosso) 1:34.793
8. Max Verstappen (Toro Rosso) 1:34.860
9. Romain Grosjean (Haas) 1:35.000
10. Felipe Massa (Williams) 1:35.006