Singapore GP: Sebastian Vettel sets the pace in opening practice

The two championship protagonists ended the first 90 minutes nearly a second faster than Jenson Button and Ferrari's points leader Fernando Alonso.

Pastor Maldonado was an encouraging fifth fastest for Williams ahead of Mark Webber in the second Red Bull.

Both Force India's impressed, with Nico Hulkenberg and Paul di Resta seventh and eighth ahead of Daniel Ricciardo's Toro Rosso and Sergio Perez's "unstably handling" Sauber.

Heavy early morning rain set the tone for the start of the session on the Marina Bay circuit, which was still significantly damp when free practice began.

Unsurprisingly. it was a tentative first half hour's running with only Jean-Eric Vergne, Romain Grosjean, Pedro de la Rosa and Timo Glock setting times on intermediates.

Alonso ended up being the fastest man on the grooved Pirellis with a 2m01.573s before Kamui Kobayashi reset the reference with a time three second faster on a set of soft slicks.

Kobayashi improved his time further and stayed top through the middle of the session, heading a timesheet that showed Mercedes's Nico Rosberg and Michael Schumacher - sporting the much-vaunted updated W03s - in second and third.

It wasn't long before Rosberg moved ahead, but as the session moved towards the hour mark, and more slick running occurred through the field, so the times tumbled.

In the final 30 minutes there was a fascinating period of running when first Hamilton, and then Vettel went fastest and the pair traded times at the top of the leaderboard.

Hamilton, who was one of several to clump over the kerbs at Turn 10 heavily, then ended his running in the pits some 10 minutes before the end of the session. No one else looked likely to challenge Vettel's 1m50.566s, though it was during this period that Button moved ahead of Alonso to go third.

There were no significant yellows, though several drivers shot off down escape roads - most notably Maldonado and Grosjean, who was 15th fastest on his return, three places behind Lotus team-mate Kimi Raikkonen.

Once again Hua Qing Ma did a steady job for HRT. On a less than grippy complicated street circuit the Chinese driver, standing in for Narain Karthikeyan, ended the session less than two seconds off the pace of Pedro de la Rosa on his first visit to the circuit.

Pos  Driver                Team                  Time              Laps
 1.  Sebastian Vettel      Red Bull-Renault      1m50.566            24
 2.  Lewis Hamilton        McLaren-Mercedes      1m50.615s  + 0.049  15
 3.  Jenson Button         McLaren-Mercedes      1m51.459s  + 0.893  17
 4.  Fernando Alonso       Ferrari               1m51.525s  + 0.959  20
 5.  Pastor Maldonado      Williams-Renault      1m51.576s  + 1.010  20
 6.  Mark Webber           Red Bull-Renault      1m51.655s  + 1.089  19
 7.  Nico Hulkenberg       Force India-Mercedes  1m51.658s  + 1.092  24
 8.  Paul di Resta         Force India-Mercedes  1m51.943s  + 1.377  21
 9.  Daniel Ricciardo      Toro Rosso-Ferrari    1m52.275s  + 1.709  24
10.  Sergio Perez          Sauber-Ferrari        1m52.296s  + 1.730  19
11.  Bruno Senna           Williams-Renault      1m52.629s  + 2.063  25
12.  Kimi Raikkonen        Lotus-Renault         1m52.716s  + 2.150  16
13.  Kamui Kobayashi       Sauber-Ferrari        1m52.839s  + 2.273  23
14.  Michael Schumacher    Mercedes              1m52.986s  + 2.420  21
15.  Romain Grosjean       Lotus-Renault         1m53.028s  + 2.462  20
16.  Felipe Massa          Ferrari               1m53.080s  + 2.514  17
17.  Jean-Eric Vergne      Toro Rosso-Ferrari    1m53.189s  + 2.623  25
18.  Nico Rosberg          Mercedes              1m53.227s  + 2.661  25
19.  Timo Glock            Marussia-Cosworth     1m54.908s  + 4.342  20
20.  Heikki Kovalainen     Caterham-Renault      1m55.091s  + 4.525  16
21.  Charles Pic           Marussia-Cosworth     1m55.335s  + 4.769  22
22.  Vitaly Petrov         Caterham-Renault      1m55.760s  + 5.194  22
23.  Pedro de la Rosa      HRT-Cosworth          1m56.656s  + 6.090  21
24.  Ma Qing  Hua          HRT-Cosworth          1m58.053s  + 7.487  20

All Timing Unofficial