Sebastian Vettel put in a late charge to beat Lewis Hamilton to the first P1 at the Circuit of the Americas by 1.4s in a practice that saw drivers slipping and sliding all over the place.
The action started early, from the very first installation lap, as the drivers slipped and slid their way around on the new surface. In fact, the track surface was so slippery that Nico Hulkenberg told his team it was like driving on a "wet" track.
Kamui Kobayashi had the honour of setting the first-ever lap time on the CoTA, a 1:54.846. However, the Sauber driver struggled to keep his car pointing in the right direction as almost every second corner resulted in a slide or a twitch. He lowered the benchmark to a 1:51 and then a 1:48.517.
Lap after lap the Sauber driver improved his time with Mark Webber playing a brief cameo in the P1 slot before losing out to Kobayashi with a 1:45.866. That was the P1 time after the first 30 minutes with Webber second ahead of Bruno Senna, Kimi Raikkonen, Sergio Perez and Daniel Ricciardo.
Webber hit the front again while his team-mate Sebastian Vettel went ninth on his first time lap and flew off the track on the second. The German, though, was by no means the only driver testing the limits as Michael Schumacher and Jean-Eric Vergne also had moments. Vettel's next lap boosted him up the order to second with Lewis Hamilton taking third. Hamilton's next lap had him taking first with a 1:42.603.
Fernando Alonso was the next to lead the way but was topped by Hamilton with a 1:40.918. As the grip levels increased, the lap times dropped, although that didn't mean the drivers were yet sticking to the tarmac with Jenson Button and Felipe Massa flying off at Turn 19. Sergio Perez had a near-miss with the pit lane entry barriers.
With 30 minutes remaining Hamilton was leading the way with a 1:40.175, 0.353s up on Button while Alonso was a further 0.07s down. Vettel was 11th but soon after improved to fourth as he ventured out for another run. Alonso upped his pace but remained third. It was more of the same as Vettel went quicker but stayed second, Alonso went quicker but stayed third and Hamilton went quicker to hold a 0.648s advantage with ten minutes to go.
Putting in the laps Hamilton went even quicker but that didn't stop Vettel from taking the P1 slot off him with a 1:38.692, which was 0.8s up on Hamilton's best and 1.6s quicker than Alonso's. And then he went even quicker - 0.5s up on his previous best - as the chequered flag fell.
01 Sebastian Vettel Red Bull 1:38.125 30 laps
02 Lewis Hamilton McLaren 1:39.543 1.418 28 laps
03 Fernando Alonso Ferrari 1:40.337 2.212 29 laps
04 Jenson Button McLaren 1:40.528 2.403 29 laps
05 Mark Webber Red Bull 1:40.650 2.525 30 laps
06 Felipe Massa Ferrari 1:40.966 2.841 26 laps
07 Nico Hulkenberg Force India 1:41.023 2.898 29 laps
08 Kamui Kobayashi Sauber 1:41.036 2.911 28 laps
09 Nico Rosberg Mercedes 1:41.159 3.034 32 laps
10 Sergio Perez Sauber 1:41.473 3.348 29 laps
11 Paul di Resta Force India 1:41.783 3.658 29 laps
12 Daniel Ricciardo Toro Rosso 1:41.825 3.700 28 laps
13 Jean-Eric Vergne Toro Rosso 1:41.833 3.708 29 laps
14 Kimi Raikkonen Lotus 1:41.880 3.755 23 laps
15 Romain Grosjean Lotus 1:41.998 3.873 27 laps
16 Pastor Maldonado Williams 1:42.539 4.414 30 laps
17 Michael Schumacher Mercedes 1:42.588 4.463 25 laps
18 Charles Pic Marussia 1:43.288 5.163 23 laps
19 Heikki Kovalainen Caterham 1:43.443 5.318 28 laps
20 Vitaly Petrov Caterham 1:43.522 5.397 23 laps
21 Timo Glock Marussia 1:44.464 6.339 24 laps
22 Bruno Senna Williams 1:44.548 6.423 29 laps
23 Pedro de la Rosa HRT 1:46.917 8.792 13 laps
24 Ma Qing Hua HRT 1:48.559 10.434 19 laps