Vettel dominated the free practice sessions but it was Hamilton who grabbed pole:

Quote Originally Posted by Practice 1
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

Singapore GP: Sebastian Vettel sets the pace in opening practice - F1 news - AUTOSPORT.com
Quote Originally Posted by Practice 2
Pos Driver Team Time Laps
1. Sebastian Vettel Red Bull-Renault 1m48.340 27
2. Jenson Button McLaren-Mercedes 1m48.651s + 0.311 24
3. Fernando Alonso Ferrari 1m48.896s + 0.556 26
4. Mark Webber Red Bull-Renault 1m48.964s + 0.624 26
5. Lewis Hamilton McLaren-Mercedes 1m49.086s + 0.746 28
6. Paul di Resta Force India-Mercedes 1m49.300s + 0.960 30
7. Nico Hulkenberg Force India-Mercedes 1m49.339s + 0.999 31
8. Nico Rosberg Mercedes 1m49.790s + 1.450 32
9. Felipe Massa Ferrari 1m50.039s + 1.699 28
10. Romain Grosjean Lotus-Renault 1m50.161s + 1.821 23
11. Michael Schumacher Mercedes 1m50.263s + 1.923 23
12. Kimi Raikkonen Lotus-Renault 1m50.345s + 2.005 24
13. Pastor Maldonado Williams-Renault 1m50.636s + 2.296 32
14. Daniel Ricciardo Toro Rosso-Ferrari 1m50.791s + 2.451 26
15. Sergio Perez Sauber-Ferrari 1m51.122s + 2.782 28
16. Kamui Kobayashi Sauber-Ferrari 1m51.450s + 3.110 21
17. Bruno Senna Williams-Renault 1m51.452s + 3.112 11
18. Jean-Eric Vergne Toro Rosso-Ferrari 1m52.00$s + 3.669 31
19. Timo Glock Marussia-Cosworth 1m52.218s + 3.878 29
20. Heikki Kovalainen Caterham-Renault 1m52.576s + 4.236 27
21. Charles Pic Marussia-Cosworth 1m52.863s + 4.523 27
22. Vitaly Petrov Caterham-Renault 1m52.936s + 4.596 25
23. Pedro de la Rosa HRT-Cosworth 1m54.448s + 6.108 25
24. Narain Karthikeyan HRT-Cosworth 1m54.514s + 6.174 30

Singapore GP: Sebastian Vettel stays on top in second Friday practice - F1 news - AUTOSPORT.com
Quote Originally Posted by Practice 3
Pos Driver Team Time Laps
1. Sebastian Vettel Red Bull-Renault 1m47.947 15
2. Lewis Hamilton McLaren-Mercedes 1m48.272s + 0.325 15
3. Fernando Alonso Ferrari 1m48.623s + 0.676 11
4. Nico Hulkenberg Force India-Mercedes 1m48.859s + 0.912 16
5. Kimi Raikkonen Lotus-Renault 1m48.865s + 0.918 17
6. Felipe Massa Ferrari 1m49.458s + 1.511 13
7. Paul di Resta Force India-Mercedes 1m49.684s + 1.737 15
8. Nico Rosberg Mercedes 1m49.699s + 1.752 16
9. Bruno Senna Williams-Renault 1m49.715s + 1.768 14
10. Michael Schumacher Mercedes 1m49.981s + 2.034 14
11. Mark Webber Red Bull-Renault 1m50.110s + 2.163 12
12. Jenson Button McLaren-Mercedes 1m50.524s + 2.577 10
13. Daniel Ricciardo Toro Rosso-Ferrari 1m50.664s + 2.717 16
14. Kamui Kobayashi Sauber-Ferrari 1m50.777s + 2.830 15
15. Romain Grosjean Lotus-Renault 1m50.840s + 2.893 15
16. Pastor Maldonado Williams-Renault 1m51.012s + 3.065 15
17. Jean-Eric Vergne Toro Rosso-Ferrari 1m51.059s + 3.112 17
18. Sergio Perez Sauber-Ferrari 1m51.272s + 3.325 10
19. Charles Pic Marussia-Cosworth 1m52.290s + 4.343 16
20. Vitaly Petrov Caterham-Renault 1m53.781s + 5.834 12
21. Heikki Kovalainen Caterham-Renault 1m54.326s + 6.379 14
22. Narain Karthikeyan HRT-Cosworth 1m54.421s + 6.474 14
23. Timo Glock Marussia-Cosworth 1m54.630s + 6.683 9
24. Pedro de la Rosa HRT-Cosworth 1m54.875s + 6.928 14

Singapore GP: Sebastian Vettel fastest again in final practice - F1 news - AUTOSPORT.com
Quote Originally Posted by Qualifying
Pos Driver Team Time Gap
1. Lewis Hamilton McLaren-Mercedes 1m46.362s
2. Pastor Maldonado Williams-Renault 1m46.804s + 0.442
3. Sebastian Vettel Red Bull-Renault 1m46.905s + 0.543
4. Jenson Button McLaren-Mercedes 1m46.939s + 0.577
5. Fernando Alonso Ferrari 1m47.216s + 0.854
6. Paul di Resta Force India-Mercedes 1m47.241s + 0.879
7. Mark Webber Red Bull-Renault 1m47.475s + 1.113
8. Romain Grosjean Lotus-Renault 1m47.788s + 1.426
9. Michael Schumacher Mercedes no time
10. Nico Rosberg Mercedes no time
Q2 cut-off time: 1m47.943s Gap **
11. Nico Hulkenberg Force India-Mercedes 1m47.975s + 1.310
12. Kimi Raikkonen Lotus-Renault 1m48.261s + 1.596
13. Felipe Massa Ferrari 1m48.344s + 1.679
14. Sergio Perez Sauber-Ferrari 1m48.505s + 1.840
15. Daniel Ricciardo Toro Rosso-Ferrari 1m48.774s + 2.109
16. Jean-Eric Vergne Toro Rosso-Ferrari 1m48.849s + 2.184
17. Bruno Senna Williams-Renault no time
Q1 cut-off time: 1m49.809s Gap *
18. Kamui Kobayashi Sauber-Ferrari 1m49.933s + 2.245
19. Vitaly Petrov Caterham-Renault 1m50.846s + 3.158
20. Heikki Kovalainen Caterham-Renault 1m51.137s + 3.449
21. Timo Glock Marussia-Cosworth 1m51.370s + 3.682
22. Charles Pic Marussia-Cosworth 1m51.762s + 4.074
23. Narain Karthikeyan HRT-Cosworth 1m52.372s + 4.684
24. Pedro de la Rosa HRT-Cosworth 1m53.355s + 5.667

Singapore GP: Lewis Hamilton beats Maldonado to pole at Marina Bay - F1 news - AUTOSPORT.com