Mercedes' Nico Rosberg came close to beating Vettel, but ultimately had to settle for second. Romain Grosjean (Lotus) stormed to third, ahead of Mark Webber (Red Bull) and Lewis Hamilton (Mercedes).
Felipe Massa, who will be replaced by Kimi Raikkonen at Ferrari at the end of the season, proved quicker than Fernando Alonso, as the pair lines up sixth and seventh. Jenson Button (McLaren), Daniel Ricciardo (Toro Rosso) and Esteban Gutierrez (Sauber) completed the top 10.
Unlike his unusually faster teammate, Nico Hulkenberg didn't make it to Q3. He lines up 11th on the grid.
Charles Pic edged Giedo van der Garde at Caterham. Jules Bianchi (Marussia) settled for 21st ahead of his teammate Max Chilton, who brings up the rear.
Before qualifying, Vettel had also topped the last free practice session, from the same men who starred in qualifying. The order that time was Grosjean second fastest, followed by Rosberg, Webber and Hamilton. Raikkonen (Lotus) failed to crack the top 10 on both occasions, as he went from 12th in FP3 to 13th on the grid.
The times in FP3 showed Mercedes struggled less compared to Red Bull on the medium compound than it did on the supersoft.
Qualifying results* – Singapore Grand Prix (Marina Bay street circuit)
1.Sebastian Vettel (Red Bull RB9-Renault) - 1'24"841 - Q3
2.Nico Rosberg (Mercedes W04) - 1'42"932 - Q3
3.Romain Grosjean (Lotus E21-Renault) - 1'43"058 - Q3
4.Mark Webber (Red Bull RB9-Renault) - 1'43"152 - Q3
5.Lewis Hamilton (Mercedes W04) - 1'43"254 - Q3
6.Fernando Alonso (Ferrari F138) - 1'43"890 - Q3
7.Felipe Massa (Ferrari F138) - 1'43"938 - Q3
8.Jenson Button (McLaren MP4/28-Mercedes) - 1'44"282 - Q3
9.Daniel Ricciardo (Toro Rosso STR8-Ferrari) - 1'44"439 - Q3
10.Esteban Gutierrez (Sauber C32-Ferrari) - no time - Q3
11.Nico Hulkenberg (Sauber C32-Ferrari) - 1'44"555 - Q2
12.Jean-Eric Vergne (Toro Rosso STR8-Ferrari) - 1'44"588 - Q2
13.Kimi Raikkonen (Lotus E21-Renault) - 1'44"658 - Q2
14.Sergio Perez (McLaren MP4/28-Mercedes) - 1'44"752 - Q2
15.Adrian Sutil (Force India VJM06-Mercedes) - 1'45"185 - Q2
16.Valtteri Bottas (Williams FW35-Renault) - 1'45"388 - Q2
17.Paul Di Resta (Force India VJM06-Mercedes) - 1'46"121 - Q3
18.Pastor Maldonado (Williams FW35-Renault) - 1'46"619 - Q3
19.Charles Pic (Caterham CT03-Renault) - 1'48"111 - Q3
20.Giedo Van der Garde (Caterham CT03-Renault) - 1'48"320 - Q3
21.Jules Bianchi (Marussia MR02-Cosworth) - 1'48"830 - Q3
22.Max Chilton (Marussia MR02-Cosworth) - 1'48"930 - Q3