Bahrain F1 test: Bottas sets pace, trouble for Red Bull, Mercedes

Williams driver Bottas traded blows at the top of the times with Ferrari's Fernando Alonso in the middle of the morning, as both drivers worked on short runs.

Bottas eventually asserted himself at the top around 11:30 local time, and both teams then switched their focus to different - and slower - programmes.

Aside from the occasional flurry of fastest times, the majority of the session had been quite straightforward until Vettel brought out the first red flag just after midday.

The Red Bull was off the track at Turn 1, and it appeared to have spun as the car was facing in the opposite direction to the track, close to the outside barrier.

Vettel was looking around the rear of the car as soon as he climbed out of it, and when it was returned to the pits his Red Bull crew struggled to roll it back into the garage.

Mercedes made a late start to the final day of running, with Lewis Hamilton joining the action just before lunch after a gearbox issue robbed the team of any morning track time.

The 2008 world champion logged five laps in the short time he had before the break, setting the seventh fastest time.

Adrian Sutil clocked the most laps of the session, as Sauber gave him an extra half-day of testing to make up for only managing one lap on Saturday.

The German was able to work on a race simulation among his 91 laps, before handing over to Esteban Gutierrez for the afternoon.

For the second day running the lunchbreak started slightly early, when the Lotus of Romain Grosjean stopped on the backstraight and brought out the red (and then chequered) flag.

Pos  Driver            Team/Car              Time       Gap      Laps
 1.  Valtteri Bottas   Williams-Mercedes     1m34.797s           60
 2.  Fernando Alonso   Ferrari               1m35.509s  +0.712s  27
 3.  Nico Hulkenberg   Force India-Mercedes  1m35.577s  +0.780s  33
 4.  Jean-Eric Vergne  Toro Rosso-Renault    1m35.701s  +0.904s  43
 5.  Adrian Sutil      Sauber-Ferrari        1m36.467s  +1.670s  91
 6.  Jenson Button     McLaren-Mercedes      1m38.111s  +3.314s  20
 7.  Lewis Hamilton    Mercedes              1m38.650s  +3.853s  5
 8.  Kamui Kobayashi   Caterham-Renault      1m38.653s  +3.856s  58
 9.  Romain Grosjean   Lotus-Renault         1m39.302s  +4.505s  25
10.  Sebastian Vettel  Red Bull-Renault      1m39.708s  +4.911s  44
11.  Max Chilton       Marussia-Ferrari      1m41.242s  +6.445s  10