After a difficult Friday practice the Williams F1 team would prepare for the final Saturday practice session for the 2013 Singapore Grand Prix. Both team drivers Valtteri Bottas and Pastor Maldonado finished well down the order with the pair seventeenth and eighteenth. With the start of the session Valtteri would come out for his installation lap followed shortly after by Pastor. It was a hotter day than Friday with the humidity even higher. Pic would be the first driver to set a time with a slow 1m:52.954 with the Di Resta the only driver yet to take to the track. Van der Gar would set a 1m:52.134 but Sutil would go fastest with a 1m:51.402. Pic would match this time to be second but Van der Gar went quicker with a 1m:50.792 to be fastest.

More drivers were coming out including Chilton, Bianchi, and Gutierrez. Di Resta had finally come out joined by Hulkenberg and Raikkonen. For Williams Valtteri would come out first followed by Pastor with nearly fifteen minutes of the session completed. A 1m:50.057 from Sutil while team-mate Di Resta would not pit and set a time straight away with a 1m:49.572 to be quickest. Both Torro Rosso cars were out on the track as Gutierrez went third and Van der Gar now third. Raikkonen was in seventh with Hulkenberg running off the track at Turn nine. Both Williams drivers were on their first timed laps with Valtteri fastest in sector two but Pastor would go quicker. Valtteri would set a 1m:48.933 to be quickest but Hulkenberg would go quicker
with a lap of 1m:48.607. Pastor would go quicker with a 1m:48.492 with Valtteri now third. Everyone was still on the medium tyre as the teams worked through further race simulations.

Di Resta was now fourth but this would become fifth as Ricciardo went fastest with a 1m:48.001. Raikkonen was now second with a 1m:48.393 with Vergne third, 1m:48.429. Pastor was now fourth and Valtteri sixth. But Valtteri was on an improved lap and would set a 1m:48.288 to be second. Hulkenberg would take this spot with a 1m:48.185 with Di Resta seventh with a 1m:48.736. Valtteri would pit after a short run. We now had both McLaren and Mercedes cars out on the track for their first runs. Vergne would improve to now be second, 1m:48.143. Vettel and Webber were also out as Rosberg went fastest with a 1m:47.516. Grosjean would go fastest with a 1m:46.883 and Hamilton moved into second, 1m:47.363. Pastor would pit currently in tenth.

Perez was in eighth with Valtteri now seventh. Perez would improve to be sixth while team-mate Button would go fifth, 1m:47.775. Grosjean was on a quicker lap joined by Hamilton. Grosjean would set a 1m:46.616 to remain fastest but Hamilton would go fastest in the final sector seeing him set a 1m:46.514 to be quickest. Valtteri said that the track had improved from yesterday as Valtteri returned to the track. He was currently in eleventh and Pastor now fourteenth. Vettel was now fifth with a lap of 1m:47.439 and Perez now ahead of Button in sixth. Both Ferrari's were out on the track as Webber went fastest with a 1m:46.220. Alonso would improve to be fifth, 1m:47.087. Hamilton would improve to set a 1m:46.445 remaining in second. Vettel was now fifth and Alonso sixth with under thirty minutes remaining.

Webber and Rosberg were on quicker laps as Pastor returned to the track. A 1m:47.019 from Rosberg but he would remain fourth. Vettel would set a 1m:46.299 to move up to second. Both Williams drivers were back out running on the medium tyre with Valtteri thirteenth and Pastor fifteenth. Splitting the Williams cars was Raikkonen with Massa was now in eleventh while team-mate Alonso was still sixth. Pastor would make a mistake at Turn two but was able to continue. Valtteri would pit after a few laps while Pastor continued to put in further laps. With seventeen minutes remaining the track was fairly empty with just a handful of drivers out on the track, including Pastor. But Pastor would pit from his final medium tyre run with just three cars on the track with twelve minutes remaining.

Drivers would start to come out for their qualifying simulations running on the supersoft tyre. We would have Grosjean, Rosberg, Alonso, Button, Perez, and Hulkenberg all out on the track. Other drivers would leave the pit lane including Vettel, Hamilton, and for Williams Valtteri. The track was now very bust with Pastor also out on the track. Fastest sector times were coming from drivers with Grosjean setting a1m:44.364 to be quickest. A 1m:45.876 from Hulkenberg to be second but Alonso would take this spot with a 1m:45.257. Sutil was now in eighth with Vettel fastest in sector one. He would finish with a 1m:44.173 to go quickest. Both Williams drivers were on quicker laps as Hamilton moved into third with a 1m:44.921. Valtteri would improve to be eleventh with a 1m:46.660 but Pastor would move ahead with a 1m:46.338 to be eleventh and Valtteri twelfth. Rosberg was now third with a 1m:44.741 and Webber fourth, 1m:44.906. Hamilton was now fifth followed by Alonso, Perez, Hulkenberg, and Button.

Ricciardo would take twelfth from Valtteri seeing the Williams drop to thirteenth. But Vergne would push both Williams drivers down one place when the Torro Rosso moved int eleventh, 1m:46.084. Pastor was now twelfth and Valtteri fourteenth. As the final minutes counted down drivers tried to complete a final lap but traffic was certainly playing its part with drivers struggling to find space out on the track. The session would come to an end as Gutierrez moved up to sixteenth. Raikkonen was on a quicker lap moving from eighteenth to twelfth, 1m:46.147. This would see Pastor and Valtteri finish the session in thirteenth and fifteenth as Pastor pitted. Both Williams drivers would complete practice pit stops as they returned to their pits. A small move forward for both Williams drivers but their pace was such that they should be able to get into the second period of qualifying but not any further. But on a positive note at least they had improved their positions over Friday.

Pos Driver         	  Team		        Time     Laps
 1. Sebastian Vettel      Red Bull-Renault      1m44.173s 15
 2. Romain Grosjean       Lotus-Renault         1m44.364s 16 
 3. Nico Rosberg          Mercedes              1m44.741s 18 
 4. Mark Webber           Red Bull-Renault      1m44.906s 14 
 5. Lewis Hamilton        Mercedes              1m44.921s 14 
 6. Fernando Alonso       Ferrari               1m44.257s 13 
 7. Sergio Perez          McLaren-Mercedes      1m45.500s 12
 8. Nico Hulkenberg       Sauber-Ferrari        1m45.876s 19
 9. Jenson Button         McLaren-Mercedes      1m45.890s 13
10. Felipe Massa          Ferrari               1m45.935s 13
11. Jean-Eric Vergne      Toro Rosso-Ferrari    1m46.084s 15
12. Kimi Raikkonen        Lotus-Renault         1m46.147s 13
13. Pastor Maldonado      Williams-Renault      1m46.338s 17
14. Daniel Ricciardo      Toro Rosso-Ferrari    1m46.358s 16
15. Valtteri Bottas       Williams-Renault      1m46.660s 17
16. Paul di Resta         Force India-Mercedes  1m46.879s 16
17. Esteban Gutierrez     Sauber-Ferrari        1m46.893s 13
18. Adrian Sutil          Force India-Mercedes  1m47.249s 19
19. Giedo van der Garde   Caterham-Renault      1m48.931s 17
20. Charles Pic           Caterham-Renault      1m49.037s 18
21. Jules Bianchi         Marussia-Cosworth     1m49.182s 21
22. Max Chilton           Marussia-Cosworth     1m49.982s 20