Force India's Nico Hulkenberg posted the fastest time on the first day of the second pre-season test in Bahrain on Wednesday.
The German posted a time of 1.36.880 on the Sakhir track, 0.999s faster than Ferrari's Fernando Alonso in second.
Lewis Hamilton was another couple of tenths further behind in third, with Kevin Magnusen in fourth, 1.415 seconds slower than Hulkenberg's time.
Sebastian Vettel was in fifth, but his best time was almost two seconds slower than the Dane's best, the reigning World Champion posting a 1:40.224.
Adrian's Sutil's Sauber was sixth, a couple of tenths slower than Vettel, while Robin Frijns, Daniel Kvyat and Romain Grosjean were the only others to post a time.
In the morning session, Magnussen set the pace, beating the Hamilton's initial time by two tenths of a second.
At that point, Mercedes-powered cars locked out the top three places after Hulkenberg posted the third best time.
Grosjean handed the Lotus E22 its public debut, but completed only seven laps before as software and battery problems put an end to his day. Furthermore, the Frenchman was out-paced by the Caterham of Frijns, who had a much longer run and completed 26 laps.
The problems continued for the Renault-powered cars, though.
The Toro Rosso suffered an oil leak, which prevented new signing Kvyat from recording a lap in the morning, while the Red Bull kept its RB10 behind closed doors.
When Vettel eventually did come onto the track - with less than an hour remaining in the afternoon session - he was only able to complete 14 laps.
Alonso was responsible for the day's first red flag when a ''fuel mix' problem in the pits left the area billowed in smoke.
The Ferrari was fourth fastest, though, just over a second faster than Sutil, who also brought out the red flags when he spun at the first turn.
Marussia's Jules Bianchi and Felipe Massa in the Williams only completed a couple of installation laps in the morning, which was delayed by 30 minutes when confusion arose over how many marshals was needed at the track.
1. Nico Hulkenberg (Force India) 1:36.880
2. Fernando Alonso (Ferrari) 1:37.879
3. Lewis Hamilton (Mercedes) 1:37.908
4. Kevin Magnussen (McLaren) 1:38.295
5. Sebastian Vettel (Red Bull) 1:40.224
6. Adrian Sutil (Sauber) 1:40.443
7. Robin Frijns (Caterham) 1:42.534
8. Daniel Kvyat (Toro Rosso) 1:44.346
9 Romain Grosjean (Lotus) 1:44.832
10 Felipe Massa (Williams) No Time
11 Jules Bianchi (Marussia) No Time