Lewis Hamilton set a blistering pace in Singapore on Friday evening to edge Mark Webber by three-tenths and last year's P1 time by three seconds.
After a very quiet start in which the drivers waited on one another to clean the track, Sergio Perez had the better of the early running.
As the first to set a time, he continued to lower the benchmark as others ventured out and had it down to a 1:50.103 when he headed back into the pits after his first run of six laps.
Pastor Maldonado was the next to lead the way before he was overhauled by his team-mate Valtteri Bottas. The Finn clocked a 1:49.510 to top Maldonado and Nico Rosberg at the halfway stage.
Seconds later though it was all change. Mark Webber hit the front ahead of Lewis Hamilton only for Rosberg to come flying through with a 1:48.684. This sparked a attle between Webber and the Mercedes drivers, who traded fastest lap times with Kimi Raikkonen also getting involved in the mix.
There were early problems for the Finn's Romain Grosjean as the Lotus driver was stuck in the pits with a steering issue that was discovered on his installation lap.
Back at the front Hamilton clocked a 1:47.055, three seconds quicker than last year's P1 time in first practice, to edge Webber while Vettel, having lapped outside the top ten, slotted into third place ahead of Rosberg and Raikkonen. Fernando Alonso, despite having a snapping rear end, was sixth quickest.
The top six then all headed back into the pits, leaving just a few drivers out on track including Grosjean. The Frenchman ventured out with 20 minutes remaining and worked his way up to seventh place and then sixth.
Coming out for a late run on worn tyres, none of the top placed drivers were able to improve their tyres and Hamilton finished the evening with in the P1 slot with his 1:47.055.
Webber was second, 0.365s down, while Vettel brought his Red Bull home in third place. He was the only other driver to get within a second of Hamilton's time.
01 Lewis Hamilton Mercedes 1:47.055 20 laps
02 Mark Webber Red Bull 1:47.420 +0.365 20 laps
03 Sebastian Vettel Red Bull 1:47.885 +0.830 19 laps
04 Nico Rosberg Mercedes 1:48.239 +1.184 23 laps
05 Kimi Raikkonen Lotus 1:48.354 +1.299 18 laps
06 Romain Grosjean Lotus 1:48.355 +1.300 12 laps
07 Fernando Alonso Ferrari 1:48.362 +1.307 21 laps
08 Sergio Perez McLaren 1:49.267 +2.212 20 laps
09 Jean-Eric Vergne Toro Rosso 1:49.348 +2.293 23 laps
10 Esteban Gutierrez Sauber 1:49.355 +2.300 21 laps
11 Pastor Maldonado Williams 1:49.481 +2.426 20 laps
12 Felipe Massa Ferrari 1:49.493 +2.438 16 laps
13 Valtteri Bottas Williams 1:49.510 +2.455 21 laps
14 Jenson Button McLaren 1:49.608 +2.553 20 laps
15 Paul di Resta Force India 1:49.887 +2.832 18 laps
16 Adrian Sutil Force India 1:50.092 +3.037 20 laps
17 Nico Hulkenberg Sauber 1:50.222 +3.167 17 laps
18 Daniel Ricciardo Toro Rosso 1:50.757 +3.702 16 laps
19 Jules Bianchi Marussia 1:52.359 +5.304 16 laps
20 Max Chilton Marussia 1:52.673 +5.618 15 laps
21 Giedo van der Garde Caterham 1:52.920 +5.865 24 laps
22 Charles Pic Caterham 1:53.647 +6.592 23 laps