Two-time World Champion Sebastian Vettel of the Red Bull Racing Formula 1 team topped the two free practice sessions of the Grand Prix of Singapore held Friday on the Marina Bay street circuit.

Vettel, driving a Renault-powered Red Bull RB7, set the fastest time in 1m50.566 on the bumpy circuit.

Sebastian Vettel, Red Bull (Photo: WRI2)

Heavy early morning rain set the tone for the start of the session, which was still significantly damp when free practice began. Then, the track dried up and the teams fitted slick Pirelli tires.

Lewis Hamilton of McLaren ranked second ahead of his teammate Jenson Button, Ferrari's Fernando Alonso and Williams' Pastor Maldonado.

Vettel's teammate, Australian Mark Webber was down in sixth place.

Lewis Hamilton, McLaren (Photo: WRI2)

The modified Mercedes AMG W03 failed to impress with Michael Schumacher 14th and Nico Rosberg in 18th place. The overheating brakes caused some issues to the engineers.

Vettel resumed his domination in the second session, topping the charts with a time of 1m48.340. The Red Bull Team tested a solution to improve the running of their alternators, and it seems that it gave positive results.

Jenson Button planed this McLaren MP4-27 in second place, three tenths down to Vettel.

Mark Webber, Red Bull (Photo: WRI2)

Fernando Alonso was third in front of Mark Webber, Lewis Hamilton, Paul di Resta and Nico Hulkenberg (Sahara Force India), Nico Rosberg, Romain Grosjean (back in the Lotus after a one-race ban) and Michael Schumacher.

Bruno Senna lightly brushed his Williams against the outside wall at Turn 19. The incident may have been small, but the stranded car proved difficult to remove and necessitated a short red-flag period.

As usual for a Friday, there was also a comparison between the two tire compounds brought here by Pirelli (Soft and Super Soft) and long runs for all drivers. By the end of today’s practice, the Scuderia Ferrari said a clear difference had emerged between the two Pirelli compounds in terms of lap time.

Sergio Perez, Sauber (Photo: Sauber F1 Team)

Grand Prix of Singapore, free practice 1*, Friday:
1 - Sebastian Vettel (Red Bull RB8-Renault) - 1'50"566 - 24 laps
2 - Lewis Hamilton (McLaren MP4/27-Mercedes) - 1'50"615 - 15
3 - Jenson Button (McLaren MP4/27-Mercedes) - 1'51"459 - 17
4 - Fernando Alonso (Ferrari F2012) - 1'51"525 - 20
5 - Pastor Maldonado (Williams FW34-Renault) - 1'51"576 - 20
6 - Mark Webber (Red Bull RB8-Renault) - 1'51"655 - 19
7 - Nico Hulkenberg (Force India VJM05-Mercedes) - 1'51"658 - 24
8 - Paul Di Resta (Force India VJM05-Mercedes) - 1'51"943 - 21
9 - Daniel Ricciardo (Toro Rosso STR7-Ferrari) - 1'52"275 - 24
10 - Sergio Perez (Sauber C31-Ferrari) - 1'52"296 - 19
11 - Bruno Senna (Williams FW34-Renault) - 1'52"629 - 25
12 - Kimi Raikkonen (Lotus E20-Renault) - 1'52"716 - 16
13 - Kamui Kobayashi (Sauber C31-Ferrari) - 1'52"839 - 23
14 - Michael Schumacher (Mercedes MGP W03) - 1'52"986 - 21
15 - Romain Grosjean (Lotus E20-Renault) - 1'53"028 - 20
16 - Felipe Massa (Ferrari F2012) - 1'53"080 - 17
17 - Jean-Eric Vergne (Toro Rosso STR7-Ferrari) - 1'53"189 - 25
18 - Nico Rosberg (Mercedes MGP W03) - 1'53"227 - 25
19 - Timo Glock (Marussia MR01-Cosworth) - 1'54"908 - 20
20 - Heikki Kovalainen (Caterham CT01-Renault) - 1'55"091 - 16
21 - Charles Pic (Marussia MR01-Cosworth) - 1'55"335 - 22
22 - Vitaly Petrov (Caterham CT01-Renault) - 1'55"760 - 22
23 - Pedro De La Rosa (HRT F112-Cosworth) - 1'56"656 - 21
24 - Ma Qing Hua (HRT F112-Cosworth) - 1'58"053 – 20

Grand Prix of Singapore, free practice 2*, Friday:
1 - Sebastian Vettel (Red Bull RB8-Renault) - 1'48"340 - 27 laps
2 - Jenson Button (McLaren MP4/27-Mercedes) - 1'48"651 - 24
3 - Fernando Alonso (Ferrari F2012) - 1'48"896 - 26
4 - Mark Webber (Red Bull RB8-Renault) - 1'48"964 - 26
5 - Lewis Hamilton (McLaren MP4/27-Mercedes) - 1'49"086 - 28
6 - Paul Di Resta (Force India VJM05-Mercedes) - 1'49"300 - 30ù
7 - Nico Hulkenberg (Force India VJM05-Mercedes) - 1'49"339 - 31
8 - Nico Rosberg (Mercedes MGP W03) - 1'49"790 - 32
9 - Felipe Massa (Ferrari F2012) - 1'50"039 - 28
10 - Romain Grosjean (Lotus E20-Renault) - 1'50"161 - 23
11 - Michael Schumacher (Mercedes MGP W03) - 1'50"263 - 23
12 - Kimi Raikkonen (Lotus E20-Renault) - 1'50"345 - 24
13 - Pastor Maldonado (Williams FW34-Renault) - 1'50"636 - 32
14 - Daniel Ricciardo (Toro Rosso STR7-Ferrari) - 1'50"791 - 26
15 - Sergio Perez (Sauber C31-Ferrari) - 1'51"122 - 28
16 - Kamui Kobayashi (Sauber C31-Ferrari) - 1'51"450 - 21
17 - Bruno Senna (Williams FW34-Renault) - 1'51"452 - 11
18 - Jean-Eric Vergne (Toro Rosso STR7-Ferrari) - 1'52"008 - 31
19 - Timo Glock (Marussia MR01-Cosworth) - 1'52"218 - 29
20 - Heikki Kovalainen (Caterham CT01-Renault) - 1'52"576 - 27
21 - Charles Pic (Marussia MR01-Cosworth) - 1'52"863 - 27
22 - Vitaly Petrov (Caterham CT01-Renault) - 1'52"936 - 25
23 - Pedro De La Rosa (HRT F112-Cosworth) - 1'54"448 - 25
24 - Narain Karthikeyan (HRT F112-Cosworth) - 1'54"514 - 30

*Unofficial timing