It is quite difficult to know what to make of the FP1 in Bahrain, but Kimi Raikkonen led a Ferrari 1-2 with the Mercs way down the order while Jenson Button had problems.
After another Lewis Hamilton and Mercedes clean sweep in China, many believed we would be in for something similar this weekend, but it was a mixed bag during Free Practice One at the Sakhir Circuit on Friday.
Hamilton and Mercedes team-mate Nico Rosberg were, as expected, fastest during the first few minutes of the session, but quite a few other drivers had their moments in the spotlight as Fernando Alonso, Max Verstappen, Daniel Ricciardo and Valtteri Bottas were all briefly at the top.
However, Ferrari saved their tyres early in the session and then had a full go close to the end and first Vettel, who spent a lot of time in the garage after reporting a loss of power, taking over at the top with a 1:38.029 before his team-mate Raikkonen went faster with a 1:37.827.
Bottas completed the top three and he was followed by Sainz, Ricciardo and Verstappen.
Alonso briefly raised a few eyebrows when he briefly went top, but the times dropped quite a bit after that, but he still managed to be safely in the top 10 at P7.
McLaren needed that good news as the other car of Button failed to post a flying lap. The 2009 World Champion had just completed his installation lap when his MP4-30 switched off and he failed to return to the track after that.
Felipe Nasr, Daniil Kvyat and Felipe Massa completed the top 10, but the Mercedes cars of Rosberg was down in P15 with a best time of 1:39.293 while Hamilton was behind him with a 1:39.532.
Behind them were Marcus Ericsson in the second Sauber and the two Manor cars of Will Stevens and Roberto Merhi while Button failed to post a time.
1 Kimi Raikkonen Ferrari 1:37.827 13 laps
2 Sebastian Vettel Ferrari 1:38.029 0.202 12 laps
3 Valtteri Bottas Williams 1:38.39 0.563 23 laps
4 Carlos Sainz Torro Rosso 1:38.447 0.620 14 laps
5 Daniel Ricciardo Red Bull 1:38.455 0.628 17 laps
6 Max Verstappen Torro Rosso 1:38.504 0.677 22 laps
7 Fernando Alonso McLaren 1:38.598 0.771 18 laps
8 Felipe Nasr Sauber 1:38.628 0.801 18 laps
9 Daniil Kvyat Red Bull 1:38.661 0.834 17 laps
10 Felipe Massa Williams 1:38.790 0.963 21 laps
11 Sergio Perez Force India 1:38.793 0.966 15 laps
12 Pastor Maldonado Lotus 1:38.842 1.015 24 laps
13 Nico Hulkenberg Force India 1:39.187 1.360 20 laps
14 Jolyon Palmer Manor 1:39.283 1.456 31 laps
15 Nico Rosberg Mercedes 1:39.293 1.466 23 laps
16 Lewis Hamilton Mercedes 1:39.532 1.705 22 laps
17 Marcus Ericsson Sauber 1:39.534 1.707 22 laps
18 Will Stevens Manor 1:42.973 5.146 12 laps
19 Roberto Merhi Manor 1:44.265 6.438 15 laps
20 Jenson Button McLaren